Why so much? My guess is cause they can. But if you would want to paint it yourself, do not go to pep boys, unless your ride was painted at pep boys.
If you can and got the money, find an auto parts shop (who can mix paint or match it) or maybe even the dealer (gasp!) give them the color code for your car. Its usually located on a data plate in your engine bay (that's where it is on a p11).
Get the rest of yer supplies i.e. Sanding paper, clear coat, the accelerator, and what not, invest in an air spray gun or go and borrow one, and that should do the trick.