Pretty much my thoughts here.
It has changed some since a number of older classic games have been reappearing, either as GBA/DS games (finally, a legit version of Chrono Trigger!), or as straight downloads (which I hate, I too prefer the hard copy). So if a new version of a game I have downloaded after I have the emulated copy, it will depend on just how much I enjoy the game if I get it or not.