With a kit and materials, I think I paid around $150. Then there is the time to strip the interior and prep and mask off anything you don't want painted.
And if they can actually do it in a day that would be great. Mine took about 4 days. 1 to strip, prep, and do the first coat, then 1 for the scond coat, one day to sit, just to make sure it was cured, and then one day to put it back together.
I used herculiner, but some of the professional spray stuff cures faster.