C.R.S. § 32-14-123

(1) Any special obligation bonds issued pursuant to this article shall be sold at public or private sale for not less than the principal amount thereof and accrued interest, or at the option of the board, below par, at a discount not exceeding seven percent of the principal amount thereof, but such special obligation bonds shall never be sold at a price such that the net effective interest rate exceeds the maximum net effective interest rate authorized. (2) No discount, except as provided in subsection (1) of this section, or commission shall be allowed or paid on or for any sale to any purchaser or bidder, directly or indirectly.