43. The actual value of a unit of assessment is its exchange value in the free and open market, that is, the price most likely to be paid at a sale by agreement made in the following conditions:(1) the vendor and the purchaser are willing, respectively, to sell and to purchase the unit of assessment, and they are not compelled to do so; and
(2) the vendor and the purchaser are reasonably informed of the condition of the unit of assessment, of the use that can most likely be made of it and of conditions in the real estate market.