As with all vans it's best to go and look at them before buying or bidding on them buy your cheap damp meter form B&Q or wherever and go searching for damp (make sure the probes pierce the vinyl coating of the wallboards)
Depending on your results you can either walk away, consider buying, even with damp especially if you think you might be able to DIY it (with the help of the fixit club here)
If the layout suits you, the condition suits you and the price suits you, you have yourself a van, if not you carry on looking.
I had a 2005 lunar zenith 4 berth, nice lightweight van to tow (Peugeot 406 2.0 petrol). Layout was OK , but the 2 seats at the back, the one by the bathroom was difficult to get into. OK for a small child.Apart from that tiny niggle, everything else was ok.