There is nothing any of us can say. A used RV should be judged by floor plan, condition and price. The name of the manufacturer or model is redundant. How the unit was treated is way more important. An RV is a house being driven down the road at 65 mph and being shaken to death. Even the best built RVs suffer because of this. That RV has has 7 years of being shaken, not stirred. Hire an RV inspector before buying and the NADA value is about $10k.
http://www.nadaguides.com/RVs/2011/Keystone-RV/M-266-RL-SSR/4116454/Values