If you are at the campsite, then don't bother hiring. There will be plenty of people bouldering, and I can guarantee that you will meets lots of friendly people who will be willing to lend you a mat. I took a small alpkit mat last year, and it found more function as a seat than a bouldering mat.
I'm going back again this summer, and have no intention of taking a bouldering mat or hiring one. The atmosphere at the campground is very chilled, so I wouldn't worry about it.