Help with valuing landlocked land
How on earth do I get a good valuation on landlocked land?
I’m in southern New Hampshire. I have an acre and the neighbor across the river has 5 landlocked heavily wooded acres on my side. There are no rights of way or easements per multiple survey companies and tax maps. This is truly landlocked and only sellable to 4 other abutting neighbors - she can’t even access it unless she took a boat or swam across the river. She wants to sell it but wants $28k for 5 acres. That, plus a 10k survey and current use penalty will bring the total cost of absorbing the land to roughly $42,500. This seems very high for 5 acres that cannot be sold on the regular market. Additionally the FEMA flood maps show roughly 1/4 of this land is in a flood plane (I have witnessed some of these floods)
How can I get an idea of value other than “what an abutting neighbor is willing to pay”