ought to be cheap by now, no?
I think Civ4 is more or less awesome but I do wish they'd have changed a few things with the resources. Agricultural and Animal resources ought to be transferable to other suitable land areas. There's no sensible reason that once I discover cows and domesticate them that I can't replicate that group of cows anywhere I want in my country. Same with rice, corn, dyes, silk, etc....
I also think the food system should be more sophisticated, at least in the late game. Some kind of national, then international, food market where some cities can get enormous while producing very little food becasue they are buying food from the market that other cities or even civs sell into. Maybe that's what supermarkets are supposed to simulate...