The one thing the seller or dealer won't tell you is all the existing warranties. The engine if Cummins is 5 years or 100,000 miles. The Allison trans has at least a couple year warranty. The chassis builder has a warranty, Freightliner is two years. Then the body builder has one usually ours was 1 year ( Fleetwood) . There is a two year on structural with Fleetwood.
So many large items like the engine are covered and the trans for a shorter period and many of the chassis items are covered for a period of time. The extended warranty people know this and you will be required to get repairs under the original warranty before they pay a dime.
It will cover other items like plumbing, electrical, hydraulic, appliances, tires sometimes, slide out motors, jacks, seals, gaskets,sewer tanks, water tanks, water heater, all the other stuff that the builder manufactures or installs.
So it's a******shoot if you'll get your money back. Most don't. I didn't want one, but my wife insisted we get it on our new MH. I think it will be wasted as the engine warranty is valid until mine expires. A generator repair could get costly or slide problems. If after 2 years we get trans problems then it could get costly too, but the Allison trans is bullet proof from what I've heard. And from what I've been hearing the extended warranty people have a set price they pay for repairs, not all dealers will accept it.