We paid for two inspections and passed on two coaches before finding our coach. You actually want two inspections- a 'house' inspection and a chassis inspection. An 'RV' inspector will inspect all the house systems, etc., but most don't check the engine, transmission, brakes and chassis related stuff. Some are better than others. I used google to find the house inspectors, and a Cummins authorized shop to do the chassis inspection (and read the engine codes). I was not at all impressed with the Cummins shop- they said I had a oil pan gasket leak and it was the main crank seal, and they missed two broken brackets such that the intake pipe was just laying on the engine. Each inspection costs $300-500.
If I were to buy again, I would what I did again- fly to Texas to do the house inspection myself and have a shop check the chassis. Buy a good checklist so you know what to look for. If you're not comfortable doing your own inspection, I can tell you this- a house inspector will always find enough problems to pay for the fee.
Walt & Bonnie
2006 Monaco Camelot 40PAQ, Cummins 400 ISL
05 Prius on Demco Kar Kaddy SS (for now)