We've removed a TON of paneling in our house. Some had been installed over the original plaster walls, some over studs. We've done all the work ourselves, so cost was pretty negligible. Taking it down was really easy. Any major cost would come about due to the condition of the drywall underneath. You could have an issue how the paneling was installed. Some of ours was just nailed on, and that came off easily. Just some holes to patch on the walls. Some was glued in addition to the nails, though. It ripped up the wallpaper underneath when we pulled it off. That was no big deal since I didn't want the wallpaper and our plaster walls were fine. I'd be a little nervous about that ripping the drywall. Still, I can't imagine it totally destroying the drywall.
Anyway, I'm really glad we did it. It a million times brighter. If I get a chance after the kids go to bed, I'll dig out some pictures.