Great question. I am sure there will be many, many people in Schenectady with the same question. You have two options to argue your assessment. You can argue that you are assessed above market value for the area or you can argue that you inequitably assessed in comparison to other properties in the area. Generally I help homeowners present a case that they are assessed above market value by providing an appraisal they can present at the greivance. (if they truly are assessed above market value)However, you can pull recent sales yourself for free and present them for comparison to your property for free. A local Realtor can help you with this or you can take a trip to the assessor's office and review sales data. Keep in mind just because your assessment went way up your taxes won't necessarily go way up. Your final tax bill will not be know until the new tax rate is released and this generally isn't until after the grievance period.