The upgrade system is rather simple. Adding a point to a stat costs $50 for the first point, and an additional $50 on each subsequent point. So, the fifth point would cost $250 (50 x 5 points) and the 100th point would cost $5000. So in total it would be $63750 to upgrade all the way. Buying new boards also increases your stats. The first new board costs $250, and each subsequent board is an additional $250. However, buying a new board changes all your boards to reflect the stats of the new board. The total costs of all the boards is $7000 or so.