I've been doing body and paint for a long time now. We just got done restoring a second gen 2500 Cummins flatbed. It cost right around 10k. However that was extensive body work, ( patch panels, fender replacement, rocker panel replacement) and bed lining the flatbed. If you do the prep work yourself you'll just be mad when they do it all over again. At least a reputable shop will. I don't paint anything that I myself or my prepper hasn't prepped. Most shops would prefer to get the vehicle untouched so that way it will all be easier going back together and so they can make sure any replacement parts/decals match the original. If all you are wanting done is the hood and bed cover, I would take them off and drop them off to have painted. I'm not sure about where you are at but here would run you about $700-1000. A good rule of thumb on the scratches, if you can feel them chances are they won't buff out and rub water over them and you'll get a good idea what it would look like after buffing. Just be careful not to buff through your clear. Good luck with whatever you decide to do.