If you take a look at my post for my 1969 Roadrunner Post Coupe Restoration, I had Line X brand bed liner installed. I went with black because I am painting the car Lime Green and will be exploiting the green and black theme. I completely grinder and wire wheeled the bottom after glass blasting and the took it to my local Line X dealer on a rotisserie. They sprayed it for me for $850. Can you do it cheaper (absolutely), but after watching the prep work and the enthusiasm on the guys face doing my car, I felt comfortable. Took lots of time and really did a nice job.
Local paint supply shop wanted $300 for the materials and then I needed a gun. To me, after getting it spotless, I didn't want to screw it up. Definitely made the right choice. Looks awesome.