By today's standards, environmentally, safety, etc., overall paint jobs are not inexpensive. The shop has a lot of overhead in just having the approved paint booth, exhaust, and breathing apparatus in play. Unless you can find the back yard shade tree guy that specializes in overalls, which I doubt is out there, you are basically captured by the paint professional and the price he wants to charge.
May I suggest a little research on your behalf. Go to the shop in question and ask if you can see some of their previous work up close and personal. Shop around, some may offer a better deal than others. Good luck with your endeavor.