X2 on the tires. Unless they have Saliuns or something similar, demand they put decent tires on. Otherwise tell them to knock off $1,000 since you'll need to replace them. If they won't, walk away. Also make sure you have an upgrade from the standard pin box - the most common Lippert 1621 has many replacement options. Also be sure and look at the suspension and have them put on a decent wet bolt/beefed up hangers otherwise you'll end up replacing them yourself. I would also see if they have stabilizers at the back. Many units will have a level-up system that goes just behind the rear tires, but nothing on the back and it can get pretty bouncy.