The board of appraisers as so constituted shall proceed to view and value the mortgaged property and all or a majority thereof shall make a sworn return within thirty days from their appointment of the true value of the property as of the date of sale, taking into consideration sale value, cost and replacement value of improvements, income production and all other proper elements which, in their discretion, enter into the determination of true value.
S.C. Code § 29-3-720