I would not estimate. Each town has a tax office and this is public record.
Here in New York, the taxes are broken down by town, county, and school district. Find out the current taxes with out any exemptions, such as a VA exemption, should be easy to get without guessing.
JoElla Deliberto, Associate Broker, Houlihan Lawrence real estate, Rt. 6 , Jefferson Valley, NY 10541