2006? While I am not familiar with the West Patreson area I do know that here in Monmouth conty only those homes sole in the previusyear not to exceeed 10/1/2008 will be considered in a apperl. You may want find yourself a tax appeal attorey that does charges only if u win (aka a contingency fee basis).
Hee in Monmouth county I refer clients to Jeff Horn for tax appeal matters.
Tomasz is correct about the CMA part from a realtor because that is the only type of analysis a sales associate is allowed to do. However, that is not a valuation of your property. Contact a local appraiser for a retrospective appraisal report. They'll do a full appraisal on that home with the effective date of June 2006 on there. But make sure you get someone who has already done some of these as it calls for a bit more specialized knowledge and expertise than current date appraisals.
An appraisal is what you need for an asset valuation for tax reasons. If this is to contest a past or present local tax assessment, contact the tax assessor for specific instructions on that procedure.
Jacobus "Jack" Vollenberg
RE Appraiser - Vollenberg Appraisers
Asset Manager - ERA Statewide Realty