With those few miles on it, it tells you that it sat most of it's 9 years. Almost certain it probably has the original tires, which means you'll have to spend $1200 to $1500 for a GOOD (meaning safe) for tires right off the bat. Add to that changing out all the chassies fluids, belts, hoses, ect (not because of milage, but because of age), thats another bunch of bucks. Then there's the wear items on the coach itself, like slide seals and baggage door gaskets that may or may not be good.
Check the generator and the # of hours it's been run. Generally it's good to run the genny on a regular basis, under 1/2 load to keep it operating properly. I run mine every 2-3 weeks for and hour or so. A genny with really low hours over a 9 year period may or may not need service, which can be expensive.
Check and recheck and re-re check the inside for leaks, get up on the roof and check for cracks/gaps in the caulking that may mean leaks. If the rig just sat most of the time, what type of maintaince and preventative maintaince would the owner have been motivated to do.
So, your at $2000-$2500 before you take your first trip. And thats taking into consideration that all the systems on the rig are in good working condition. Lack of use also plays havoc with rubber chassies bushings.
You could probably start on the middle area of what NADA lists, always bringing up the items that will need to be replaced, and the cost.
Have the owner hook up water and elec. to test the systems, and check the fridg for operation on elec and gas. Appliances for these things are expensive, an ac unit can run $600-$1000, a fridge will set you back a grand. Fans, tv's, range, water pump, ect. all can go with lack of use and no maintaince. Water check the faucets and tanks for leaks.
Just depends on what kind of condition the rig is REALLY in. Just because it LOOKS like new dosen't meen bupkis.