I know unfamilia is joking - but don't use kill rust (or any other epoxy enamel anti rust type paint) on the 'topside' of the car. It is an excellent strong resilient paint for the underbody/suspension but it has one weakness (if you could all it that) and that is that it fades (a lot, and quickly) in direct sunlight.

And the next thing you'll learn is that acrylic won't go over enamel properly, and you'd have to strip the lot back to get anything like a good surface prep.

On the cost side of it - seriously allow a couple of hundred for paint/thinners/clear - about $300 might just cover it, but could come in closer to 500. Then of course there is labour. If someone doesn't charge a decent rate, it's either because you are a close friend, or their skills aren't worth big money - at least that is usually the case.

Unlike practically anything mechanical which can always be rectified later on when you have time/money (not always the best idea, but certainly true) - the paint, you're 'stuck with it' for years unless you want to start again from scratch. So it pays to put some dollars into it (which is probably why my cars both need work on the paint side of things!)

If you are looking to really save, you could consider getting some flat or satin black, spraying yourself then a few coats of clear. The good old 'drift spec' paint job. And satin/flat blacks will hide a lot of imperfections in body/prep/paint skills quite well. But that colour/look is certainly not for everyone!