Super System 1/2 or both

SS 2 is really the only one you need, the players that buy SS instead of 2 are trying to save a couple of dollars is all I can figure, Super System solidly outsells Super System 2 on Amazon but really I don't understand why, SS2 is more current with games that are current today, The original fills in some gaps but because those games are not widely spread and the NL section is essentially the same only buy SS 2 IMO