Depends on what you want to use it for. I can't find it but there is a video out there on how they build "stick and staples" rv's. And YES they literally are STICKS STAPLED TOGETHER!
I have nothing against that, my parents have a very expensive highend rv motor home, it is very nice, but not for me. I chose to go with a gmc motor coach bus. I think Skoolie's are great as well.
They both have their pro's and con's. Depends on what you want to use it for.
Buses are way cheaper in the initial purchase price than a solid rv. There are always exceptions, but generally this is true. But then you have the conversion price. This is where things can go crazy depending on what you want. If you actually counted man hours and put a shop rate to that then an rv will be much cheaper! But some of us (crazy us lol) actually get a very high level of pride and satisfaction of building it our selves. Plus we know the bus inside and out and can fix it easier and cheaper "when" there are problems. Most rv's aren't meant to be lived in, they were built for the occasional weekend trip.
One other thing to consider is if your going to be using "commercial" camp ground's. A lot have a NO BUS and/or NO RV OLDER THAN 10 yrs old policy. We have already decided that we just won't use their facilities in our 50yr old bus than lol. So consider that in your decision making as well.