In '01 the Paint Dept. in Chino was painting coaches for National. I ask what a paint job like one of those and they said $13K. Your estimate sounds like a good deal.
What are you getting for your money. There is a reason for great ranges in price. Single stage enamel paint is relatively cheap compared to the base coat clear coat systems. How many colors and how complex of a pattern also plays a part in the price. Paint ranges from $50 a gallon to $500 a gallon. Is there any prep work required? If you are having scratches or body work done can also complicate things. So a good answer would be "depends".
I suggest you check with the Mfg of your Rexhall (??) to me and see how much they would charge to repaint one of there products.
I have found Mfg prices a lot lower on my 05 KSDP.
JOT