I watched a show about tiny houses. In order to get around zoning laws they have to build them on a trailer frame. A lot of these people spent 40-50 thousand dollars building the equivalent of a starter RV. It you’re going to spend that kind of money, why not just buy an RV?
That is because these people have no clue how to use re-purposed lumber and windows and such.
A local guy built one for use in a permanent camp site using used and re-purposed materials and his total bill for the entire project including paying someone to transport it to the resort was 21,000 dollars. And that included the big screen tv and all the special appliances.
Some of these people go and buy a brand new trailer frame for over 5K (and up) when you can buy a used rattle-trap RV trailer for under 1k and you can tear it down and re-purpose the lumber and wiring and plumbing. Then you go to the nearest re-use center and get the rest of your lumber and materials.
I saw the show as well and was astonished at the prices.
A couple of years back I purchased a used 25 foot travel trailer for a little north of 4K. Used campers are priced like used boats.