A friend of mine that has done tint for 25+ years used to do a good amount of vehicles for dealers. They kept trying to get him to lower his prices lower and lower. He went and looked at some of their window stickers while waiting once and saw how much they were charging and immediately stopped doing work for them. IIRC they were charging 4x what they paid him or a little more. I am sure this varies for many reasons and that was about 10 years ago.
Didn't do anything on the windshield. The car had been tinted before and no rear interior panels at all. Defroster was perfect. Other than dealing with the sticky black silicone on the rear quarters, it came out pretty good.
Perfect? But better than average
I've had multiple graphtechs and rolands of various sizes. The graphtechs are my cutter of preference. The 8000 and 8600 were the best iterations imo. I test ran a 9000 and couldn't justify the cost vs what few new features it came with. Other than a new (already outdated) control screen and a different designed stand, I didn't think much of it. They all cut within a high degree of accuracy. The variables to accuracy are usually the blade,material and feed rate. I wouldn't spend the extra coin unless I needed a big write off.