@AyWoSch Motors,
You never said anything about keeping it pristinely original did you? I don't think so. You were talking about being a sliding around in the dirt country boy who worked a pickup truck like they were designed to be used, right? Then don't worry about resale value, keeping it original looking (I think it's beyond that), or a working show truck either. None of those things. If you need to get more time out of the bed then send it a pro bed liner spraying place and get a pro job on it, and don't be concerned about anything else. You want it to last, then that's what you will get.
Actually I like what
@45tt suggested that if you are going to be carrying something heavy and or pointed that might dig into the coating, then get you a good mat like he's showing and throw that in the bed before you leave. And when you get home and done with what you needed it for, pull it out, hose out the bed, hand the mat up to dry, and go in and have a beer. It's a work truck. Then use it for work, not nothin' else. Then you won't be worried about it if the spray on liner gets scuffed or not. Gee, that's what it's for, so the paint won't take the damage.