A kart for 300,000!?!?!?!? Too bad I bought mine already...
Jackechan: 300k for a mario kart is a GREAT deal. Mario karts are 10,000 TNPs. On a regular day(With out 5x specials) its 1,000,000 bells of items from nook. On 5x day, its 200k.
Foreign fruits, fishing, turnips, etc. It's not that hard to make money in the game... This is nothing compared to how much you'll need to pay off everything.