All state lands shall be sold on terms and conditions established by the board in light of market conditions. Sales by real estate contract or for cash may be authorized. All deferred payments shall draw interest at such rate as may be fixed, from time to time, by rule adopted by the board, and the rate of interest, as so fixed at the date of each sale, shall be stated in all advertising for and notice of sale and in the contract of sale. All remittances for payment of either principal or interest shall be forwarded to the department.