Each race has 30 levels, and each of the levels require the following amount of XP (and gives the listed rewards at each level). [Image credit Existor on the Team Liquid forums][2]

![Starcraft 2 rewards and level breakdown][1]

The total amount of XP required is *4,750,000 XP*. And, as you noticed, the increase of points goes down as the levels get higher. The increases are as follows

 - *40k* starting at level 1
 - *20k* starting at level 2
 - *10k* starting at level 6
 - *5k* starting at level 7
 - *2.5k* starting at level 15


  [1]: https://i.sstatic.net/y05VX.jpg
  [2]: http://www.teamliquid.net/forum/viewmessage.php?topic_id=399876