Why don't you get them to throw in a extended warranty as part of the negotiation process on the used unit?
Basically an extended warranty boils down to you pain threshold and how much of a gambler you are. Everything has an eventual chance of breaking, especially the cheap stuff they use in a camper. Within the 1st year, I had mine in for 3 separate issues. All fixed to varying degrees of customer satisfaction.
That being said, I don't think it would have cost near the difference of $3K which is the difference you're looking it. More than likely, since it's a year old and most things are defective/repaired within that time frame, so you're probably good to go.
Do a thorough inspection of the used model to ensure EVERYTHING is working as designed and negotiate hard with them to lower the price and include a warranty if you choose. There is more than $3K worth of depreciation anyway.
