Figure the going shop rate of $130 per hour. It would have to go to one shop to have the running gear items you mentioned to be checked and then to a second RV shop to check for things like roof condition, water leaks, awning conditions, window leaks, leveling hydraulics, tires etc. Check the air conditioners and thermostats for correct operation. Get the refrigerator checked to make sure it cools properly. Get the generator checked and have the its power output checked. Make sure the engine alternator is properly charging the house batteries. This will probably run you four hours at the mechanical shop and six hours at the RV shop. With all of the taxes and shop supplies used it will be around $1,600. This cost does not include any work that needs to be done.
If you really want to be a diligent owner, after you buy it you should do all of the following so you start off with a clean slate:
Changes oils in the engine, transmission, leveling hydraulics, rear end and front wheel hubs.
Change all of the filters in the above components.
Change the both fuel filters and carry two spares.
Change the fan and alternator belts and carry a set for spares.
Change the antifreeze and filter. Old or the wrong antifreeze will eventually ruin your engine.
Do all of the above for your generator also and carry spare filters.
Get slide seals lubricated
When I got mine, I changed out both the house and chassis batteries so I knew everything was good.
There's a lot more, but this will get you started.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.
