OK it's 10 years old. So check the history of maintenance on everything. The engine should have had the plugs and boots changed by now, no matter the mileage. Oil, oil filter, air filter, Engine gas filter, Power Steering fluid, Bake fluid, transmission fluid, Generator oil, generator oil filter, gen air filter, gen gas filter, check the tires for date of manufacture (they date out after 7 years no matter how good they look), Coach and Chassis Batteries (all coach batteries should have same date) (all batteries should be no more than around 3 years old).
All of the things I mentioned can cost you a pretty penny if not done, tires alone run about $2400, Transmission flush $400, Brake flush $400 and so and so forth. These are all maintenance items that are required by this time in the life of MH.
The other things to check are all of the systems working properly, Dash AC, roof AC's, refer, all tank indications. Look for any discolorations on the ceilings (signs of water damage, roof leaks) climb on roof and check all of the caulking around all of the fixtures and look for gaps in it.
There are more things to look at but the list is long. The model overall was very good and dependable.
But remember, it is a MH and it got used a lot so it will not be perfect.
Check NADA for suggested price and compare to what they want. IT's always a good place to start.
Good luck and may the MH Gods be with you.