Should I purchase an RV warranty?

I did it once. Found out there are a LOT of ways they can deny your claim. Also that 7 year extended warranty is actually only 5 years since you said you have a 2 year factory warranty. If you calculate that money then research what items really go wrong after 2 years, you should find that it is better to put that money in the bank to draw interest then use it for repairs, you'll probably find yourself ahead.

Also, that "refund" should you decide to cancel; is applied to the back of the loan so you won't see any refund until you sell it.