I just repainted a kra3800, for comparison here's my cost, keep in mind I **** painting so probably used a little more material here and there. I did not do the insides, just everything you see.
28 bucks pint of valspar 2k single stage
45-55 bucks for quart of HOK DTM primer
25 bucks or so for both hardners (2 separate)
12 bucks or so for grease remover as I was out.
I didn't expect but used almost all of the primer, was hoping to use 1/2 for another project, but I was filling in and laying on thicker in some places to fill in some rust pits so I didn't have to go the body filler route.
I expected and used every last drop of the single stage, I was short, I skipped shooting the bottom with color, just left it primer, not going to see it anyways. May go back and shoot that when I paint some other things.
Materials was strip discs 4*4 bucks at HF, and some sand paper, masking paper, tape.
On a 54" box I'd figure a quart of color may do it, might be close. More primer, though I probably wasted a bit there as I put it on pretty thick. I think you can only get dtm primer in quarts and larger and it's not cheap. bc/cc would seem cost prohibitive compared to the value of an older box. I can't imagine paying someone would be worth it (just IMHO), unless they just did a quick sand and shot it, it would seem a bit labor intensive to me.
I don't know how you could do the fronts and not mask, you'll have primer and color all down the drawer sides. I masked right behind the drawer lip and back to make sure I shot the drawer side edges. It's time consuming, I just did a quick mask as i quickly realized to do it perfectly would be more time than it's worth (to me). To not have the drawers look like **** you have to pay attention to the pulls and sand really well there, underneath that lip there are areas you just can't get to, I sanded briefly there and cleaned really well and relied on the surfacer to clean it up (no one will look there anyways).
In hindsight on an older box unless it has some sentimental value or you just want to do it, I think it's more trouble than it's worth considering what newer boxes go for on craigslist. Advantage is I can pickup some steel cabinets cheap, paint those and shop lights to match to kinda of give it a theme. Or some other older side boxes. Though you couldn't pay me to do the insides and drawer sides,etc, and I probably wouldn't do a larger box again, the drawers are a pain. Main box EASY, drawer prep a royal pain.