From Where Do The Most Valuable Stamps Come From?

Hi everyone,
My knowledge on philatlie is extremely limited but I involved myself in an interesting project at university where I need to identify collectibles trends in Europe.
Considering stamps as leader of the collectibles pact, I would like to know from which European countries do the most valuable stamps come from? Top 5 countries?

Many Thanks in Advance!

The same place where the top 5 art paintings come from,
and the top 5 pottery pieces come from, and the top 5 jewellery
countries. etc etc.

I think that is very hard to determine. However the countries that have the best chance of meeting your objective would be those that:

1. have a large population
2. have a tradition of stamp collecting
3. have a cadre of worldwide collectors who like their material
4. have not issues zillions of stamps and in very large quantities
5. were an early adopter of postage stamps for payment of mail delivery
6. have a tradition of turning out high quality stamps, souvenir sheets and other related collectables

Here is my take!
Countries that still exist.
1) Sweden
2) Switzerland
3) Finland
4) United Kingdom
5) France

Dead Countries
1) Geneva
2) Basel
3) Zurich
4) Moldavia
5) Mecklenburg-Strelitz

My house, let me give you a quote :)