This sure holds true in motorcycle painting. If you include all the materials (paints, reducers, sandpaper, cleaning thinners), it averages out to about $150 for a single color or about about $250+ for a basic custom paint job, don't think that you will get a 'show quality' custom paint job for $600. There is alot of labor and steps into doing the job RIGHT! If the price is low, then obviously some of the steps were not taken in order to make the job right. Or, the materials chosen for the job were not the best available.
If you purchase a 'cheap' inexpensive paint job job, you're going to get a cheap job.
Corners, steps and quality of materials are cut!
Once you have it painted and find out it's not to your satisfaction, then it's too late! I've heard this WAY too many times!