It's just my opinion, but since you asked... I would not recommend getting an extended warranty for any type of trailor. Everyone's budget threshold is different, but compared to an RV with a drive train, there aren't many high-dollar things to go wrong. By the time you pay the deductible, schedule the appointment and take the RV in, you can usually fix whatever went wrong yourself - for the same amount of money, or less... and you learn about your RV in the process.
We have an extended warranty (through Easy Care) but the only reason we have it is because our RV has a drive train. Replacing the engine, for example, could cost more than 50K, and a catastrophic transmission failure would also be costly. The fine print in most (if not all ) extended warranties is carefully worded to exclude covering a lot of things, so if you decide to buy one, read it carefully.
Kev