Is this a good Class C?

The first thing to do is go to nadaguides.com and under the RV section find the make and model and check the price. Forty eight thousand miles is not a lot of miles, so it has a long life left in that engine. The more important issue is how was it maintained. Was it covered? If the roof needed to be resealed then was their a leak? Probably. Look inside around vent frames and look for a brown stain line. Especially check the overhead cab are for leaks. A rig thats been driven is much better than one thats sat for 8 years. Check all the appliances, especially the refrigerator which is a spendy item. Look for documentation of maintenance and oil changes.