Underwriter issue

I live in a peculiar subdivision as that we have a private airstrip runway. I built a very nice home within, and there are are maybe 12 homes which are on from 3-5 acre lots. There are perhaps another 12 available lots for sale (with no activity) Some people fly and have planes, others do not and there are no issues whatsoever) With have an HOA with decent rules and restrictions. So my house is in process of selling when buyers underwriter puts on the brakes, deeming the area not marketable and concerns with the common areas, and comps the appraiser came up with, bout 6 days before closing. Being it a rural area, and no comparable homes are available, it seems this combination of things has put both realtors with buyer and I in this god forbidden situation. House is 330K with them putting down 75k conventional loan. Basically this lender (small in size) is most likely worried about selling the loan. So we have been told that the buyer really wants the home as they've went ahead and bought furniture, just for this, otherwise I was thinking perhaps they changed their mind and was waiting for the contract to die and walk away. (which is entirely possible) Sucks that we are all packed up and ready to move, yet stuck! This place is marketable. People dream of living in a place like this, out in the open, with community ponds and freedom. An underwriter sitting in his office can only go off of what the appraiser comes up with, and this appraiser from a larger city. It has not been flatly turned down yet, but thinking it's headed that way as I don't know how underwriters mind can be changed. Geesh! Maybe time for buyer to find another lender, or maybe they will be convinced to approve? What a pain in the butt. And our home appraisal came in at asking price so know that isn't an issue. Oh and my loan current loan is not assumable. Any comments are welcome.