I just went to IGN, and they have sales reccords of all RE games on GCN, and things look promising for RE4, sales I mean. RE remake, and RE0 both sold about a million copies world wide, but the straight ports of RE2 and RE3 have only sold about 100k copies combined. Considering the straight ports costed next to nothing to port, I would assume even those were profitable, selling for $40 each.