I guess a lot depends on what you want and what it's going on. If it's a 57 Chevy convertible or a Hemi Superbird then you can spend $1000 a gallon and laugh about it but when I repainted my car trailer recently I went to Tractor Supply and got the $30 stuff. I'd throw a person out of the shop that wanted to el-cheapo the paint on a Duece 3 window.