I manufacture cabin kits. Many are completed on site by myself, some are completed by the end user. We pre-build everything possible that still allows transport to remote locations. Everything is pre-cut, pre-stained, and pre-built as much as possible. Very little cutting is required on site. My customers include private land owners as well as government campgrounds.
The most popular cabin kit is 12x16 with an attached 6' covered porch.
Difficult to estimate...$10,000?