Rustoleum satin black (or gloss, matte, or any other rattle can) is cheap, and can be used on your sliders and skids too.
I used this stuff. Cheap and readily available.
I don't mind spending the money or time if it lastsCoat it with mud! Rustoleum is fine if you don't want to spend much. My ARB had some poor powder coat in a few places and started to rust immediately, it was all in hidden places I only saw because I was up under/behind it wiring lights but still pissed me off. I sprayed the heck out of it, so far so good.
I do the same thing with the frame, skids, tow hitch, etc. on occasion.
If you want to go full guinea pig - check out the powder coating kit from harbor freight and let us know how it works. I am going to check it out when I get sliders.
YOu have to bake powder coat. Unless you have a giant oven with convection laying around... Not gonna work.
That said, the HF powder coat gun is great. I use a big toaster oven with convection to bake the parts (after sandblasting) And have restores many motorcycle parts this way.