If you like them enough go ahead and buy them. I do that and I don't mind spending a pretty penny on a single game if I felt it was worth it.
I see games as a work of art and regardless of how common they are or rare they are if I really like a game enough I will try hard enough to add it into my collection.
I only collect game based on my enjoyment of it. I'm not going to go out there and say purchase a game that goes for 200$ on ebay just because it is rare.
I too sold off some of my saturn goodies but then later ended up buying them back and paying even more than I sold it for but at the same time, I consider the games a form of art and even if I don't play it often I can still go back and play it later in the future.
So I would recommend collecting them all again if you feel they are worth owning. If not just download it.