Make certain when you pick it up that the dealer thoroughly explains how everything works. For example I bought an older Class A (I'll admit it was for a bargain basement price). I couldn't get the levelers to work and used it for 8 months assuming that they needed repairs (like nearly everything else on the rig). Actually, all I had to do was set the emergency brake before I operated them and they worked just fine! It sure would've been nice if the dealer had had the professionalism to thoroughly go through the rig with me before I left with it.
Steve