Door to Door Realty
Market value is generally determined by similiar properties that have sold recently rather than those currently for sale. Your area realtor who specializes in vacant lots can give you a market value of that land.
Keller Williams Preferred Realty
I would agree, contact a local professional (preferrably 3) and have them provide a Comparable Market Analysis. You will get a range of value from each. The property will vary in value depending upon location, amount of wetlands, utilities, water/sewer, road, etc. There are many variables.
The first place to start, would be your property assessment notice. Double that figure and you will have the amount Conklin area government has valued the land.