How to value a stamp

Of course, you already know the answer to this.

Take your chosen catalogue, find the stamp, check the value, deduct a decent percentage from the inflated price in front of you and…Voila! Easy.

Except the world has moved on and a catalogue (less percentage discount) is no longer the most accurate way of determining value. A far more precise measure is to refer to actual selling prices in the arena in which supply and demand are most accurately reflected.

Yes, I mean eBay.

Not so long ago I’d have been somewhat dismissive of using eBay’s Sold prices as a means of valuation. There were just too many ways in which prices could be falsely reported:

• Misdescribed stamps or wrongly categorised stamps

• Misrepresentation of condition (one man’s ‘fine used’ can be another man’s ‘space filler’)

• Under or over-priced stamps whereby the buyer either got an amazing deal or paid over the odds

• Inflated prices when two desperate buyers battle it out to win the prize

• Stamps selling at artificially low prices from an auction ending at 3.00 in the morning

• Different catalogue numbers quoted for the same stamp

And so on. Too many uncontrollable variables to determine whether the sold price truly reflected actual value. Except for one reason.

Critical mass.

Stamp Market Index

eBay has recorded the Sold price of every Buy It Now stamp and auction lot since 2004. Now, with hundreds of millions of transactions recorded over more than twenty years, it has the ability to provide collectors with a unique resource in helping to determine the price point at which a stamp should be bought or sold at.

Sure, all the outliers remain on the database. But if you are looking to purchase a MNH Scott 123 and there are fifty listings, thirty of which sold between $40 and $50…well, that’s probably going to be the going rate, whatever the catalogue says.

Every day more listings get added and the greater the critical mass becomes.

Interestingly, the database also acts as a very good indicator of scarcity and, hence, potential undervaluation in the catalogues. Let’s say you’ve been looking for a Scott 456 for what seems like forever. You check on the database and find that only two copies have come to market in the past 20 years. That $15 dollar value in the catalogue probably doesn’t reflect the scarcity of the stamp; nor the higher price a collector may well be prepared to pay to secure it.

I first discussed Stamp Market Index (a subsidiary of Noble Spirit) upon its launch in 2019 and if you’ve yet to explore it, it is definitely worthy of your time. It continues to remain an important weapon in the collector’s armoury.

(Check it out here if you have yet to try it).

Stamp Market Index is fine for checking prices of regular catalogued items but what about the rare, the obscure, the one-offs? The material that one only really sees at the larger auction houses? Well, the major auctions aren’t doing a bad job of maintaining their own historical datasets either. For example Corinphila provides catalogue data going back to 2011, Cherrystone to 2001, David Feldman to 1976 and Siegel all the way back to a remarkable 1930.

Why is this relevant?

Simply because it highlights the impracticalities of attempting to keep published catalogue prices relevant in today’s world. Small teams of editorial staff cannot hope to keep pace with a dynamic market across millions of price points.

Keeping catalogue pricing current

You may be familiar with the editor’s attempt each year to keep the catalogue fresh by stating in the introduction that there were no less than 1,000 revisions in Country X, Country Y was reviewed with increases across the board, whereas Country Z was looked at closely and saw a 50/50 mix of increases and decreases. The fact that 95% of the catalogue remains unchanged is quietly overlooked.

To pick but one random example (inspired by the image at the top of the article): the 1889 President Soto Alfaro set from Costa Rica (Scott 25-34).

In the 2009 Scott catalogue, this set was valued at $135.10 mint. In 2015 it was $135.10. Five years later in 2020 it was still at $135.10. And in 2025? You guessed it, $135.10.

That’s zero appreciation or depreciation in over fifteen years. And no impact from inflation. In the real world, we know that it is highly unlikely that there has been absolutely no movement in price whatsover. It is simply that a review of the issue hasn’t happened.

It’s an impossible task. I have every sympathy with the editorial teams that must align a limited resource with the decisions on what to focus on and what to ignore.

And to be fair to Scott, they made nearly 2,700 value changes to Costa Rica in 2024. Maybe the Alfaro set was reviewed and a conscious decision was made to leave the price alone after seventeen years. But I’m not so sure.

The last figures I have (from 2018) highlight that Scott covers over 700,000 listings from 600 issuing entities. Of course, it will be significantly more after a further seven years of wallpaper issues. Interestingly, Gibbons, Michel and Yvert are silent on the total number of issues they cover.

It’s easy to see why publishers would be reluctant to align catalogue values with prices originating from online sales though: along with the radical change in approach there would be some significant reductions. Witness what happened last time Scott tried this…

The Great Pricing Reset

In 1988, Scott undertook a major revaluation of its U.S. and worldwide stamp catalogue prices, particularly slashing the listed values of many modern, common and lower-grade stamps. These were not token adjustments—some catalogue values dropped by 30–70%.

This was the most dramatic pricing overhaul since the catalogue’s founding in the 1860s.

Scott stated that the catalogue values no longer reflected realistic market prices. For years, prices in the catalogue were based largely on dealers’ input, historical inertia and assumptions—often reflecting asking prices, not actual selling prices.

Several factors had converged including an oversupply of the millions of stamps issued during the boom years of the 1950s-70s and the consequent dealer inventory glut.

The new, corrected prices forced dealers and auctioneers to reprice entire inventories, often at a significant loss on paper. Many dealers protested vehemently, especially those who relied on the catalogue to justify pricing to customers and dealers with large stockpiles saw their inventories devalued overnight.

The end result was that, whilst painful in the short term, it helped re-anchor the hobby in realism and transparency. It helped spur a more data–driven and condition–conscious market and Scott regained credibility as a pricing authority.

Nearly forty years later and I would posit that the market is leaning towards a similar watershed moment, whereby true retail transparency becomes more the norm as we move away from the reference values of the past.

A major change in pricing policy at Stanley Gibbons

It’s interesting to see how Stanley Gibbons are now wrestling with the vast gulf between their catalogue pricing and true retail prices.

Once upon a time, Gibbons defended their catalogue prices by claiming that they were effectively their own retail prices, not market values per se. Tougher to defend that stance today when Gibbons has pulled out of retailing worldwide stamps and is focused on narrow segments of Great Britain and the Empire.

However, their forthcoming 2026 GB Concise catalogue is highlighted as showing “the largest restructuring of Stanley Gibbons catalogue pricing for over 20 years”. And they’ve publicly acknowledged that “the prices in the catalogue had grown too far apart from the levels that are being traded” with “reductions in price reflecting a correction from previous inflated levels”.

It’s a frank admission.

But it does illustrate the challenge that publishers now have in balancing stated catalogue prices with the transparancy of the open market.

Not so long ago, our public libraries contained groaning shelves of reference titles: everything from business information directories, through to Who’s Who and the ubiquitous Yellow Pages. All these books are either now long gone or no longer acquired but the stamp catalogue has hung on, a familiar reminder of how we used to source information in those pre-web days, let alone pre-CGPT.

But as public libraries continue to cut back, the viability of continuing to publish an annual catalogue diminishes.

That isn’t to say that the catalogue itself is redundant though. It’s main role as a source of identification remains and, although the pricing can often bear little resemblance to reality, a very quick glance enables the reader to understand price proportionality.

For example, if there are ten values from 1c to $1.00 in a set and they all price at under $10.00, apart from the 3c Used which is valued at $100, then we know that one particular stamp is disproportionality more valuable than its bedfellows. Whether $100 is the correct price point is not the question. It’s having the ability to quickly understand how much more valuable one stamp may be, relative to the remainder of the set.

The future of stamp catalogues

Where then, do catalogues go from here? If I were an editor, I’d probably be looking at three areas of exploration:

Harnessing AI

AI was built to mine, make sense of and add value to data. Mining the wealth of digital philatelic data that now exists (and that will only continue to grow) possibly isn’t top of Sam Altman’s to-do list. But it’s easy to see how a far more accurate methodology for valuing and pricing could emerge based on actual transactions, given the right focus and appropriate partnerships.

Extending the depth of catalogues

A subject in its own right but, if you use a specialist catalogue alongside one of the mainstream titles, you quickly realise how much information is missing and could potentially be added. Increasing the number of varieties listed, data on fakes and forgeries, postal history, print volumes, proofs….the list goes on.

The potential downside (for the publisher) is that this does morph the catalogue into more of a handbook and probably deducts from the necessity for an annual edition. But as collectors migrate to online sources for pricing data, this may well become an inevitability.

Stanley Gibbons again reflect a changing market. Discussing the well-respected Commonwealth & British Empire Stamps catalogue, Hugh Jefferies (its long-standing editor) writes in the August 2025 GSM Magazine: “…while remaining the company’s price list, the catalogue has become more and more of a work of reference, with many users professing to have little interest in the prices”.

Developing Chinese editions of worldwide catalogues

If you’ve ever attended a Chinese stamp show (or checked out videos on YouTube) you’ll know that the scale and potential of the Chinese market is remarkable.

The major stamp shows of recent years in the West have typically pulled in collectors in the low thousands. For example, the annual APS stamp shows will average 1600 to 2500 visitors. Stockholmia in 2019 was particularly noteworthy with just over 7800 attendees and if we go back a decade, NY 2016 recognised just over 23,000 unique visitors.

Compare that with the World Stamp Expo in Wuhan in 2019 which registered in the region of 400,000 visitors. There’s a debate to be had around whether these were unique visits and the methodology of the counting but the differences can’t be ignored.

China is arguably the fastest-growing and most strategically supported philatelic market in the world today. The country’s scale, state support, and cultural integration of stamp collecting give it a unique momentum—potentially positioning it as a future global leader in philately.

However, the current demand and focus is still very much on Chinese material, thematics and an emerging interest in some of the popular classics (= Penny Blacks). It’s not surprising though: collecting without an international catalogue to refer to doesn’t make life easy.

A worldwide catalogue in the Chinese language though? Now that could really stoke demand.

Valuing stamps using catalogues is probably not going to change much for those that don’t want the hassle of checking online and are happy to rely on a quick look-up. But as the availability of ‘real world’ pricing becomes more accessible and algorithms can make sense of the ever-growing mass of data, the printed catalogue will have to change to survive in its current form.

The next stage in the evolution of the catalogue is probably moving to a print-on-demand model which doesn’t necessitate the same level of capital upfront costs whilst still enabling collectors to access the most current iteration. In the meanwhile, the major publishing houses will continue to push collectors towards their digital offerings.

Personally, I would lament the published catalogue’s eventual disappearance. I hope it doesn’t happen. There is practicality, sentimentality, history and nostalgia tied up up in those detailed pages. My ideal set up will still be computer screen to the back, stamps to the front, catalogue to the side. It works.

But as for relying purely on a catalogue to assess a stamp’s value? Not any more.