The first thing that needs mentioning is that cargo vans make horrible camper vans. Passenger vans are a much better choice… Better ventilation via opening windows, and no holes in the roof needed. They also have a pre-finished interior that you will never be able to improve upon.
It sounds like you are considering purchasing new or at least newish. The depreciation will kill your investment. You will rarely lose money on a fully depreciated van.
Depreciation aside, the last few generations of vans have been going downhill in the reliability and longevity departments. While a warranty might be nice, even brand new vehicles can be full of bugs. A warranty doesn’t help much when you’re stranded, and maybe without a home. Warranty work usually comes last, not first, and the wait times can be very long. I found this out the hard way on a couple of new vans.
I reverted back to a second generation Dodge Maxi-Van, and it’s been one of the moves I’ve ever made. Computerized BS left me stranded too many times, and they get worse every year.
I would also suggest a 1 ton van, so you always have plenty of capacity, plus they are just plain built better. For the slight difference in price, there is a huge difference in durability. Size matters too, and an extended length body can make life a lot nicer.
Keep us posted…