Question: Is a 300-400 dollar console worth it for Mario Kart and Breath of the Wild alone?

Short Answer: Yes.

Long Answer: Yes, and also buy it for a bunch of other games like the Neo Geo games they have on the online shop, Puyo Puyo Tetris, and a bunch of other stuff they have coming out.

Seriously, for Nintendo to pick themselves up from the failure of the WiiU and to do it so fast, is astounding.