I sold RVs for nearly a decade.
1. Maintenance, maintenance, maintenance, MAINTENANCE. Re-seal every seam and seal every single year, or you will have leaks and water damage. Period, end of discussion, no gray areas. Use the right sealant, too - NOT dipshit's "Flex Seal" from the TV ads.
2. Diesel is the way to go, if you want to pull or haul anything. You can get small B's (factory-body vans), small C's (van cab with a motorhome box body), and super-C's (based on 5500 and 6500 series Internationals, like HD tow trucks) with diesels, as well as the large class A pushers. The super-C's and the pushers are usually ISB or ISX Cummins motors, with some still using the Cat motor in the pushers. The smaller diesel units are typically the Mercedes Sprinter chassis which are SUPER-efficient, if not "pull a house" powerful. But they can still pull a small toad (as in "towed" - wrangler, prius, something to zip to the store so you don't have to pull up stakes on the 'house' to get a six pack). Most C's and small gas A's are - as noted - Ford V10s or large GM V8s. That's a function of the chassis manufacturers getting supply from auto manufacturers; it's just the way things go. Don't even think about fuel economy on a gasser, it'll just make you cry.
3. Drivable versus towed comes to personal preference, as noted above. Driver, you have whole-house access while going down the road; towable, you have a built-in city vehicle when you unhook.
ANY of them will be expensive, if you get a quality piece. There are some brands that are, quite frankly...crap. Others are absolutely spectacular. Winnebago is good quality with outstanding support, anywhere you go. Newmar (motorized) is near the absolute top of the heap. Keystone RV makes outstanding towables of every price point and style (TT, FW) and some of the nicest are the Montana series, and the Raptor toyhauler series. Another outstanding towable brand is Grand Design - ALL of their stuff is amazing. Airstream is overpriced for what it is (frankly), but if you want that iconic look they're kinda the only game in town for that.
You'll go dizzy looking at floorplans.
Find someplace you can do a test-tow or a test drive.
Short-bed trucks, get a slider hitch if you go fifth wheel. Spend the money, and get an automatic slider. Trust me.
Get a generator.
Make sure a) you don't mind doing the sewage pipe work every single trip, or b) you get family members to guarantee they will help you with the sewer pipe so you don't have to do it every single trip. It is not a fun job. You can stay mostly clean....but not completely. And yes, you ALWAYS close the valve, let it fill up, then dump it. NEVER leave it open - all that does is let it dry out, crust over, and create blockages.
Learn to winterize.
Do your seals every year.
Lube your slideouts every trip (rails, mech, and seals).
Run your generator 3-4x a year to keep the fuel fresh in the carb (gas, diesel, or LP - they all need to be run). Avoid Generac like the plague - their RV units suck. Cummins, or nothing.
Maintain the chassis (axles, bearings, brakes, hitch, tires; engine, trans, air brakes (pusher)).
Rent if you can. For more than a weekend - immerse yourself in it, I'd say no less than a 7 day run including at least a day drive at each end. That way you get long hours towing/driving, then setting up, using (including water and sewer work), tearing down, hooking up, and a long drive back home.
It can be fun. I know people who cannot and will not live without it. If you love it, and your family loves it...take the time (and money) to do it right, and everyone will enjoy it.
Personally? I take a motorcycle. Left saddlebag is 3 man dome tent, and clothing. Right saddlebag is a 10 degree bag that packs smaller than my head, more clothes. Top case is rain gear, toiletries, and riding gear. I camp near a stream and keep a mesh bag and a plastic bag, so I can dunk my food and keep it cool in the fresh water. I can do a week out on the bike - THAT is camping to me, not solid surface counters, 3 air conditioners, heated floors and six slideouts. If I had to do a camper, I'd be a popup guy. If I'm camping, I like to be PART of nature, not isolated from it. Tents are perfect for that.
To each their own.
