I paid $425 for over the rails line x from Line-x of Brandon, FL. I will say they didn't do that great of a job. My truck was recently hit (while parked, grrr) and had to be resprayed. The shop here in OH did a much much better job. They charged 450 - which the insurance company picked up.
I also had my RDS tool/tank combo box line-xed as well and I couldn't be happier with how it came out. Now I won't have to worry about chipping the weak powdercoat they come with (mine was black powdercoated), and it matches the bed nicely. It looks so much better than I thought it would. One of these days I'll update my reader's rigs with pics of it. I highly recommend that you guys with toolboxes have them sprayed to match!