That seems like a fair price if they did the prep! An expensive car paint shop will likely be expensive, and a cheap one might not have the sharpest spray techs, so they might have the same problems as a novice bike painter at home, trying to spray a really odd bunch of contours when they are used to cars. The key to spraying a bike is to do it in maybe one minute intervals over the course of several days, and a car shop might not want to leave your color in their spray rig for that long, so they kind of need to be used to spraying in the nooks and crannies without dumping on too much because they want to finish the job in an hour. Remembering that Mike said in his OP "I don't even care if it's not that well done (this isn't a segment where there's any resale) but just not gloppy." By these standards and with good prep, it is very doable at home.