I usually don't chime in on paint, simply because I'm no painter and would never claim to be. However, it appears to me (and any of the painters on the forum can feel free to correct me) that the major cost in a paint job is, wait for it, the PAINT!! I own a business in the petroleum equipment industry and have often thought about the money made on any given liquid (gas, diesel, etc.). Well, paint ranks WAY up there. As the OP stated, $1100 per gallon of paint (and that may very well be "cheap" paint).
And that is JUST PAINT! Not to mention the necessary reducer, and good clear isn't free either...when we painted my 69 BOSSSVT in 2010 the paint and supporting chemicals were over $1800....and that is my wholesale account cost!