I try not to. If a game is difficult to get, though, I might. Actually, now that I think about it, they released Chrono Trigger on the 3DS, didn't they?
I have no recollection of Square or Nintendo releasing it onto the 3DS, but there is a port of the game for the DS. You could get that one, or you could get it from the Wii's Virtual Console for about $8, if you have a Wii.