I had a friend who is manager at a local Chevy dealer. When they first reopened the shop it was a little slow. I referred a customer to him as they generally do nice work. The left side of the '86 Monte SS had some paint contamination. The car was 'spot' refinished in a few areas over it's life time. My estimate was to repaint the entire left side of the car. Where there was original paint, it was a little thin and some of the factory primer was visible. Oh, and the car was BLACK.
When I write my estimate on older cars, I R&I everything. It something will fall apart, I replace it (i.e., door weatherstrip). So my friend calls and mentions the guy brought the car in and they scheduled an appointment. Then he says he sold him a repaint for the whole car (Nooooooooo!). He said it was no big deal. He talked to the customer and he just wanted a good 'driver' quality paint job. The agreed price was $5K total.
I think most body shop guys know the difference between show and 'driver' quality. Customers do not. I took my buddy out to that Monte Carlo and asked him what he saw. He said a 24 year old Monte Carlo

. I advised him that it was actually a 2010 Corvette ZR1. He looked at me like I was crazy. I had to tell him that 'driver' quality to a guy with an older car is new car quality (hey, a new car is a driver, right?). He made the owner happy, but he lost his ass on that car.
The cost to replace the quarter panel and the rockers would normally be $1100 at $40 per hour. So now there is $6900 left to paint the car. I don't think paint and materials would be $3K, but $2K would be about right. Deduct the materials and you're down to $4900 to paint the car. Do you see a relationship to the Monte Carlo above? That Monte Carlo didn't need the floors painted, the aprons painted or the rest of the engine compartment. The shop didn't charge near enough for a show quality paint job.
Now this isn't the fault of the customer. If the customer wants a show quality paint job, that's what you write for. I don't know what the shop was thinking. And no part of that paint job was show quality. The other part is weight. If this car is to be abused, paint adds weight. I had a powdercoater do the pulleys for my engine in the wrong color. He said he would redo it. He wasn't happy when I advised I expected him to restrip the parts. If a shop screws up, it should be on them. Again, I pay no one upfront for anything. If they've been paid, cars sit and the shop is less than motivated to fix their screw ups.