We ran a caravan hire business for several years, although our market was not for the 'tour' industry but the 'spare-room-for-granny/on-site-office' market.
Our deliberate target market were the lower socio-economic groups.
We were buying the type/style of caravans you showed above because they were cheap; no-one else wanted them.
Never paid more than $2000 for any individual van. (Then rented them out for $35 - $40 per week...you do the maths...people are stupid.)
Those same caravans are now back in vogue, commanding figures around the $10,000 mark.
Yep, people are stupid...just wish I'd hung on to eight or ten of them!

Thanks for posting those Steve.