The amount required to be paid for redemption of property from any sale for taxes as provided in this chapter, or the redemption price, shall be the amount paid for the property at the tax sale, as shown by the recitals in the tax deed, plus any taxes paid on the property by the purchaser after the sale for taxes, plus any special assessments on the property, plus a premium of 20 percent of the amount for each year or fraction of a year which has elapsed between the date of the sale and the date on which the redemption payment is made. If redemption is not made until after the required notice has been given, there shall be added to the redemption price the sheriff's cost in connection with serving the notice, the cost of publication of the notice, if any, and the further sum of 20 percent of the amount paid for the property at the sale to cover the cost of making the necessary examinations to determine the persons upon whom notice should be served. All of the amounts required to be paid by this Code section shall be paid in lawful money of the United States to the purchaser at the tax sale or to the purchaser's successors.