I know the owners and have been in this rig and camper with them. My objective opinion is that this camper has many great features and a functional build out with many more features and functions that shown in the ad. While the materials are fairly simple, there was a lot of thought put into all of the details, wiring, lighting, etc. Owner Parker who thought thru everything is a genius with many thoughtful design ideas and functions that an ad just won't convey. There is an upcoming story on the Tiny Home Tours channel of this rig that better shows many of the thoughtful details they put into it. I would never hesitate to see a vehicle in person if seriously considering to purchase as the ad shows so little compared with seeing it in person.
For one to build something comparable including your time and the base rig, etc, it would probably cost at least as much as they are asking. Realize, time is usually at least twice the cost of the materials, and materials and rig alone are less than half of their asking price. They've also worked out many of the common issues with these retired LMTVs, which are plentiful and frequent from the many folks that I know that own them and have turned them into campers.