We went through the same discussion when we decided to try RVing. Getting serious sticker shock when we priced rentals, we decided to buy a used class A instead for short money. We bought the green machine last year and at the quoted rental costs for a similar model, we're already ahead having taken only a dozen trips.
We figure we can sell it for what we bought it for and only be out the cost of upgrades and insurance. Already looking at newer/bigger class As for next year.
If you already have the cash saved, and I know that was tough to do, then don't just give it to some rental company.