The Machinery Act requires each county to conduct a reappraisal of real property (land, buildings, and other improvements to the land) at least every eight (8) years. As part of the revaluation process, all counties are required to appraise real property uniformly at its true value in money. True value in money is "the price" estimated in terms of dollars at which the property would change hands between a willing and financially able buyer and a willing seller, neither being under any compulsion to buy or sell, and both having reasonable knowledge of all the uses to which the property is adapted and for which it is capable of being used.
Simply put, this means when two people trade land for money, both knowing what can and cannot be done with the land, and an agreement on the price is reached and the trade occurs, market value is established. Market value is not necessarily the price for which a realtor may list the land, nor is it the price for which a father may sell his son a piece of land. Market value is generally determined from sales between unrelated and unbiased buyers and sellers. This is commonly known as an "arms length" transaction. Sale through auction or foreclosure is not considered "fair market value."
The Machinery Act requires counties to appraise all real property uniformly. If comparable properties in your neighborhood are being sold in the $150,000 range and there are no significant differences in your property and the comparable properties, it is reasonable to believe your property may be valued in the $150,000 range. It would not be fair or equitable to appraise your neighbors recently purchased property at $150,000 and assess your property value at far less because you purchased your property several years ago.