Ok, for those that have never heard of Malthus, he introduced a theory (a long time ago) that basically stated that society's population will eventually outgrow their ability to produce food... in short, it never proved true because the theory didn't account for changes in technology that allow food production to expand at a much more rapid pace than he ever imagined. That said - what about coins? mintage is squared away when a year is over - barring restrikes. So your population is a set number that will, over time, only decline through loss, damage, circulation wear, and destruction. Will it ever come to pass that certain "key date", low population, coins will actually become truly hard to find, among a sea of fellow numismatists?
I suppose eventually that would be true, but if were still finding ancient Greek and Roman coins then you can bet that 2000 years from now someone, somewhere, somehow, will come across some long burried and well preserved coin collection.
Well, the obvious answer to that is that when you have economic conditions of raising demand but stable supply, you have raising prices as the result. We know that with key date coins we'll have a more or less steady supply. They won't become harder to find, just more expensive to buy (which may make it seem that they're harder to come by that is).
