Tynan has started a new lifestyle here. You would be at least #8 now or something. Quick thoughts/qs
1) What's your home city going to be? Are you planning on staying there mostly?
2) How good are you with DIY?
3) How steady is your income?
In the long run, I would say it's cheaper to live in the van/RV, but there can be a lot of nasty surprises in the beginning that can cost a lot of time and money. I mean we are talking about living full time in a 17 year old vehicle that was never intended to be lived in full time. So be aware of that and make sure you have the cash and time to deal with those unexpected challenges.
I've seen a few converted vans but never actually got to inspect them closely or talk to the owner. I feel like this might be really great if you know what you're doing and have the equipment. For the tanks you would have to jack the van pretty high to get a tank installed somehow. Also, just size wise, it's not as nice as a RV. You won't be able to stand up anywhere and will have considerable less space. On the plus side, you can park anywhere without worry and your car repairs will be much, much cheaper.
Showers are the bane of every van dweller. Your tanks get filled very quickly unless you route the water to street although that's technically illegal. And a water heater takes up so much energy that you can't have hot showers. There are tankless propane water heaters but I haven't found anyone that successfully installed on on their RV yet although I'm sure it's possible.
Finally, I'm open to selling my RV if you want. Mechanically I'd say it's probably just as good or better than any other 96 Rialta out there since I just got a full tune up, tires, muffler, rebuilt transmission, and the works. Repairs were over $6k. Coach side, there's a few maintenance repairs I'm planning on doing. But I already got the wooden floors and solar panels which is like a 3k+ value right there. Could use a propane heater and a better DC frig though. I would sell it for 12k+ but definitely not expecting 20k or anything.
I'm still on the fence with the thing. I would like to keep it but it would be more of a seasonal thing rather than a full time living vehicle....I don't know. I could install the propane heaters and the winters might not be so bad. Summers are still impossible though unless you're in San Diego. It's just unbearably warm inside during the day. Right now I'm planning on moving into my friend's house and just keeping the RV covered in my parents' driveway.
Also, last note, the joy and challenges with RV living are amazing. I was super productive while living in the RV ironically since I didn't have much else to do. I reconnected with a ton of old friends across the US and meet a few others that I expect I'll know forever. I know I'm painting a bleak picture but only because it's so easy to only imagine the benefits of a RV and not realize all the things you take for granted with an actual home. Nevertheless, it is a great experience, and I feel like a changed person for the better for it.