I had the bed of my truck Rhino lined a few years ago and I also paid a bit extra to have them run the liner up over the lip of the bed and down the side about an inch. This covered up the spots where I commonly banged up the paint and let me get rid of my lousy plastic bolt-in bedliner which had sanded down the paint pretty badly (sand and off-roading vibration). I don't remember the overall cost, but it wasn't particularly cheap.
The lining has survived several years of Arizona sunlight. It's not as dark a black as it was, but it has held up well. It gets spots when I spill oil on it (difficult to clean), but a dust storm or running down a dirt road drys that up after a while :-).
The only thing I don't like is that the old plastic bedliner was so slippery that it was easy to slide heavy things in and out of the bed, while the new lining is more rubbery, which prevents stuff from sliding out unexpectedly but requires more work moving heavy stuff around.
Here's an idea for you. The next time you need to haul something heavy look up a local sheet metal shop or metal supply house and have them cut you a piece of galvanized 24ga. (or 22ga if you haul really heavy things) a little bit smaller than your bed. The liner will hold the metal and you can slide anything you need in or out. It should'nt cost but about $30 for a piece of metal that big. Just don't forget and drive down the interstate with the metal loose. Sheet metal flys really good. Don't ask... <img src="/forums/images/graemlins/lol.gif" alt="" />