[amlib]

The difference here being that those enhancement carts would likely cost less then 20$ to manufacture and would either cost a little more then that when sold individually or cost a little bit above the price of a full game when sold bundled with a game.

I can see how this would create some confusion when buying games (which may be a deal-breaker for nintendo), but I also see more potential in this approach since these carts would be "seeded" by Nintendo's own high volume and highly sought after games, thus getting much more traction than the big console accessories of the competition, which cost around (not 100% sure) 150$. Also, as another poster noted, the n64 had the expansion pak (not too far from the idea of an enhancement cart) introduced a few years into it's life which would end up being bundled with a few games and get fairly wide support on many newer releases, tough most of the games opted for optional support to unlock extra features.