Used purchase tips?

Vehicle service records. Check Tire date codes. Test every single switch, faucet, pump, stove, fridge, hot water heater, put slides out and in but check under slides for rot, check roof all seals, check ac, heat system, open every cabinet check for water damage, check floor look for soft spots, put jacks down and up check for leaks and make sure they stay up, look at ceiling for water stains, drive it, Generator was it serviced does it have hours on it low hours are not good most times does it power unit, check batteries how old are they do they have water in them, check awnings do they operate properly on slides and over doors, check dash ac on max ac when driving. That should keep you busy for awhile and don't be afraid if you do need to repair or replace normal things like an awning etc just make sure the price has that factored in.