The game nneds to incentivize buying the intermediate cars. Because the jump in price from one car to the next is always $2000, the price of two lvl 1 races, the player has no reason to buy any cars other than the last one. The level difficulty should increase faster, the gap in car price should increase faster, and the reward money should be adjust to those other two values.
You should be able to see your interest rate at the bank. I think Santa enacted a law making it so banks had to disclose that information at the north pole.
Penguins live at the South Pole :D