Ok... number one- It's a lot easier to cross two subspecies than it is to cross two species. Carpondros are much rarer than either jungles, greens, or junglexdiamonds, therefore they are more expensive.
number two- When you cross an albino to an anery, you get hets. Then you have to breed the hets together, only one out of 16 of the babies will be a snow. As you can see, snows are a LOT of work to produce, therefore they are rarer and more expensive. The price should start dropping as more snows are produced.