Rubik's cubes are already sadistically hard. Do we really need to make them harder? I mean, just look at this brain Rubik's cube: instead of colors, you match up the grooves in the surface of the brain.
Tyson Mao might have some sick Rubik's Cube skills, especially when he solves it behind his back with his eyes blindfolded, but I'd like to see him try Shapeway's ginormous 17 x 17 x 17 Rubik's Cube.
Saving your money is an important habit to get into. Being able to pull that money out on a rainy day? Also pretty darn essential. One of those two things might give you some trouble here, depending on how you feel about solving puzzles.