You are free to appeal the Board’s decision to a court of law. However, under Connecticut law you must first appeal your case to the Board of Assessment Appeals before the appropriate Court will consider your case.
Sec. 12-63d. “Change in assessed value of real estate. Relationship to sale price. The assessor in any municipality may not, with respect to any parcel of real property in the assessment list for any assessment year, make a change in the assessed value of such parcel, as compared to the immediately preceding assessment list, solely on the basis of the sale price of such parcel in any sale or transfer of such parcel.”