re: "Investment" - I think on an older Sportsmobile van in great shape, you can expect to get about 60 to 70% of your conversion cost back at time of sale, say in 5 yrs, (if we are still allowed to own private vehicles or ones that run on fossil fuels. Hmmm - maybe I need to keep our 7.3 diesel! It can always run on McDonald's french fry oil!) This is the amount over and above what the SMB would be worth today in 2wd.
The alternatives are Transit AWD/4x4 or Sprinter AWD/4x4, or finding an already converted SMB..
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added. BlingMyRig.com