my one buddy painted a 55 chevy about 10yrs back, and just the paint and materials was a tad over 7k then.
that includes everything, primer, sealer, paint, clear and thinner. sandpaper and a little bondo was included as well, but that was just a TINY bit of the total cost.
the paint color was red, and as all know, red is the most expensive color there is.
materials have SKYROCKETED since then for ALL materials involved.
back then, JUNK thinner could be bought for $10-15.00 per 5 gallon can. we used that for general cleaning.
last fall, the same brand JUNK thinner was $50.00 per 5 gallon can.