I know of at least one "approved" approach (
GPS-A PAN) approach in mountainous country (MSA 9300ft) which was designed by an interested GA pilot because the home airfield didn't have an approach. They got the books out, designed and test flew the approach themselves, then got the FAA in to validate it. The FAA came in with their test plane and approved it, cost to the airport/pilots a big fat zero. So it can be done by rank amateurs, but I'd only fly it myself once the "experts" had validated.
No met observer needed on the ground either, what a strange thing to do.