>"Well, already you have "loads of people" claiming that kobe beef is better than regular beef (or that the black iberian pig is better than other kinds of pig). Yet, since meet from those animals is expensive, in practice the vast majority of meat doesn't come from these species.

Having just been on vacation in Malaga (highly recommended), Jamon Iberico Bellota -- the highest-quality ham from acorn-fed black iberian pigs -- is absolutely, genuinely so superior to lesser hams that it's not even funny. There is just no comparison.

It also costs at least €130/kg even the smallest local ham stores, so yes it is prohibitively expensive, you can expect to pay at least twice that for the genuine stuff, if you're not in Andalusia.

How much of the taste is because the diet, and how much is because of the breed? Who knows, but I think it's a combination.