Condition is everything on an old RV. You are buying an old, old house, albeit one on wheels. Just inspect it carefully, especially the "house" stuff. Roof and window leaks, working appliances, upholstery & flooring, etc. Since you are a newcomer, hiring an RV inspector would be a wise choice, though maybe hard to justify on a relatively low-priced RV.
For that vintage of vehicle, expect awful fuel mileage. Probably in the 6-7 range if everything works well. The 460 should be sound (if reasonably cared for), but I would check the transmission closely. The 3-speed + OD automatics of that era were rather heavily stressed moving big RVs and often got overheated. Owners also tend to neglect transmissions moreso than engines.
2004 American Tradition; 2014 Buick LaCRosse
Homebase in the Ocala Nat'l Forest near Ocala, FL