And my two cents on price. Most of these unbuilt seem to be in the $18-28k range. May need to do a bit more to demonstrate the added value of your build or adjust price.
I found this relevant...
Quick questions about ceiling height. I think the standard for these is only 5'6". Does that mean you found 4" above the drop ceiling? Is there any more height to be found/made?
These are a recent trend, buy a reasonable Fuso 4x4 and bolt on a cheap camper, instant camp vehicle. Great idea really. The whole point is it's cheap and easy.
But now people are asking a premium for their Franken-campers. However, none seem to be selling at the inflated prices.