"need to charge"
curious as to the value of the parts (probably acquired wholesale) and the man-hours to build.....
I realize other factors at play in that $25K price tag such as overhead, R&D, and he's in business to make a profit.
Anyone care to guess....
I've not clue, but here's my guess... I've a hard time imagining the parts cost him more than $3,750 and requiring more than 80 hours to build.