With about 75,000 miles (120Kms), you can figure on many of the major components will need replacing, if not replaced already. Besides shocks, ball joints and brakes, the engine and transmission may not last another 75K. The house components, such as the frig and water heater, will typically start failing at 10 years, give or take. The flip side of this equation is you can do the repairs yourself and save a considerable amount over a new coach.
Preventive maintenance is the key issue here. A well maintained coach is high miles is preferred over a coach with low miles where preventive maintenance was ignored. It is very important for you to check the roof for any past or present leaks. Any evidence of same deserves close attention.