Mediterrean countries cannot afford to pay finders for coins?

Many commentators understand the lack of market payments for coin finders in source countries tempts them to sell coins on the black market. Risky, but better than no payment! The obvious solution of paying finders market rates for coins is considered too expensive. Source countries are 'too poor.'

Wikipedia gives the GDP of the United Kingdom, 1870, at 100,179,000 'international dollars'. International dollars, also called Geary-Khamis dollars, aren't something that can be collected but are 'equivelent' to 1990 US dollars in purchasing power.

Wikipedia gives the GDP of Bulgaria, 2008, at 92,894,000 (Purchasing Power Parity). I believe that's also in Geary-Khamis dollars but I'm not sure.

So the UK of 1870 was a little richer than Bulgaria now but not by much. In terms of population, the 1871 population of the UK was 31,845,379 and the current population of Bulgaria is 7,640,238. So the per-capital GDP of Bulgaria today is actually three times higher in 1990 dollars than the UK in 1870!

A letter from the Royal Numismatic Society to the Lords Commissioners from 1871 argues that paying the finder less than the market value causes destruction: “... the practice of the Treasury in giving to the finder the intrinsic value of the objects found, virtually concedes the principle of their being his property, but, at the same time, does not prevent the constant concealment and destruction of coins and other antiquities; for the mere fact of a claim to them being advanced, accompanied though this may be by the promise of payment for them of an unknown sum at a period always indefinite and often remote, suffices in many cases to deter finders from openly producing the results of their discoveries, and drives; them to dispose of such relics clandestinely.”

I picked Bulgaria because I've heard they are considering a market system for coins. I hope it happens. They are not poor by historical standards.