That has always been my philosophy too, I just finished painting mine! But I don't see a paint gun? Are you gonna brush it on?
I have $300 guns and $15 guns, and there is very little difference in how they spray, both will paint a car fine for a hobbyist. Experience has taught me you can never have enough paint guns, always have a CLEAN backup gun for anything you are spraying.
Also something like the Dupont PPS system is a life saver for a beginner.
[ame]http://www.amazon.com/3M-16001-PPS-Standard-Collar/dp/B000AO0MTA[/ame]
You'll need the hard cup outer shell, liners, lids and gun adapter, but well worth it, you can spray upside down and at any angle without paint dripping out the top of the cup or not spraying at all.
Rage gold is good, but Rage Ultra sands better, best filler on the market IMO. Likely depending on how bad the body is (or how good you are), you'll need two gallons anyway. For a fill primer I really like Evercoat Feather Fill Polyester primer. It is good stuff.
Are you doing a base clear job?