For the most part extended warranties aren’t a good move. A few people with bad luck come out ahead while most would be better off setting the money aside for possible repairs and they won’t spend it all. You have other options, too. You can buy later, or from a third party, and sometimes from the manufacturer. Although I’m not sure how common the latter is in the RV industry.
It’s more of a peace of mind thing than a good financial move, but if you’re inclined to go for it it’s critical you read the fine print like a lawyer. Between the deductibles, caps, and exclusions, like “A’ isn’t covered if it fails because of a failure of “B” you may have less coverage than appears on the surface. Lastly, there’s serious money in selling the warranties and you can negotiate the price like anything else.