Have a friend selling his 2005 38ft DP for $68.5K. There is absolutely nothing wrong with it mechanically. Whenever there was an issue, he had it fixed right away and keeps up on his maintenance. Seems like he had an issue every once in 2 years or so. I know it is above your budget, and I'm not trying to sell it for him. The point I want to make is that there are 15 year old RVs that are reliable and up to date on all their maintenance if you just keep looking for them. On the other hand, another acquaintance has a 2013 DP that can't seem to go more than 200 miles without breaking down, Of course, he doesn't do maintenance as he thinks it's "stupid" to spend money on it if it isn't broken.
Look for the first, avoid the second.
1999 Newmar MACA 3796 F53 6.8L
2016 Ford Edge Sport
Roadmaster Sterling A/T with Brake Buddy Select