And the most important thing, BONDO!!!!
The guy will put you back a good amount if you get a good one with a good size, but don't skimp on gun quality to cut costs!!! Look at paintscratch.com to get paint prices, and the rest of the stuff is not big deal.
On top of all this, you're going to have to learn how to paint, and that will take time, some money, and effort, definitely the hardest part.