Quick tips on stopping the rust on the cheap

I like Rustoleum oil based paint. It's cheap and it WORKS. You can get it in the gallon container from Lowes for less than 30 bucks. I would even brush it on. If you do it carefully, it will dry so you will not see the first dang brush stroke. It's tough as hell too, when applied properly. The trick is sealing the metal from the air. If you do that, you can win. You can also spray it on, if you so desire, but IMHO, for a rust preventative, brushing it on coats the metal better and gets into the small pits better.

Opinions vary, but that's mine from personal experience.