Long post with lots of good advice. As you research the topic, I strongly suggest you think hard about what you want to do with your RV.
For me, it's all about getting to the choice single track mt bike trails or the best surfing beaches. Camping at these spots almost always means no hook ups (utilities), very rustic restrooms - pit toilets at best, and rough dirt roads to access the sites. I love going for a big ride or long surf session and getting back to my sheltered camper van with cold beer in the fridge and nice soft bed to rest in.
I'm a big fan of the VW Eurovan (had the VW Vanagon Westfalia before that) - so pretty much a 'class B' RV. As others have mentioned already, these are expensive and it's easy to sink tons of $$ into them if you can't do the maintenance / repairs yourself. I'm an obsessive DIY kind of person and do just about everything myself. For the things I can't do (body work, A/C recharge, etc. I research out economical places to get it done). I bought my '99 Eurovan Camper for $14,500 and used it heavily for four years adding over 95,000 to the odometer. But I sold it a couple of years ago for $18,500. Arguably, it was in much better condition when I sold than it was when I bought it. I had put over $3,500 and many hours into it so it really wasn't a money maker, but it wasn't a money sink either. My current '02 Eurovan Camper cost me $18,500 and I've put about $1,100 into it so far and I've got a few more improvements in mind - for me - half the fun is making incremental improvements on these rigs. I do want to highlight that it's easy to sink a lot of $$ into these vans if you need to get them fixed at the dealership and they are not for everyone. But they work well for what I want to do with them. When I'm not out on a trip I park it in my garage and I use as my every day driver around town. Small and easy to drive. If I wanted to sell it today, I'm guessing that I could get more than $20K for it.
I contrast this with my dad who owns a 35 foot 5th wheel that he tows down to Arizona every winter behind his GMC 3/4 ton diesel truck. He and my step mom wouldn't be caught dead in my 'tiny' VW van. They like to go down and find a low cost RV park (or sometimes boondock on BLM land) almost always surrounded by tons of other old geezers who are escaping cold weather and are perfectly happy to just be in a sunny and warm place. Entertainment for them consists of swap meets, dances, and the occasional hike. I would be a fish out of water in this environment and my camper van is not good for these massive parks nor is it comfortable around a bunch of massive RV's with their generators running. But different strokes for different folks I guess. Anyway, my dad loves having a newish 3/4 diesel truck and would own it even if he didn't have a 5th wheel. His 5th wheel was bought used for around $35K five years ago I think and the way he takes care of it, it will last him for years. I doubt that he spent more than 1 or 2K with repairs or maintenance over this period. On the other hand, they spent a bunch of money taking it up to Alaska a few years ago on fuel and park fees. Would have been much cheaper in my van in my opinion. I wouldn't dream of taking his rig down the narrow highways in Baja Mexico or down the bone jarring dirt roads in Canada, Mexico, Utah, Colorado, Oregon, etc. that I've been down in search of nice bike trails, kite surfing spots, and hot springs.
So again, there are very different use cases for the 'RV Lifestyle'. Think carefully about where you want to be, and then pursue the right RV / camper for that purpose.
