I would skip this van. I tend to agree with Simplesez above. These old E150's are a dime a dozen. Maybe 2 dozen, they just aren't where you happen to be right now. I could find you 50 tomorrow for $1k in the Southeast. Plus, it looks like it probably smells like ass.
If you want to convert to 4wd find an e250/e350 and be willing to travel. There are about a hundred stories on this forum if you dig deep enough where recovery missions (trips to pick up a van somewhere far away) have made amazing memories for people.
On the flip side you could buy this one (I wouldn't offer half what he's asking) and go with it for now leaving as 2wd to see if van life is for you guys. Don't be afraid to upgrade.
Either way you'll get lots of help and support here. Glad to have you along.
You have spoken and people here will help you find what you're looking for.