WHAT DOES HYDROMX COST? 07/07/2022 by Hydromx usually costs 2–3 times greater than traditional glycol. With Hydromx’s energy savings, the price difference comes with a payback that is usually around three years. In addition, Hydromx has received utility rebates to help pay for this energy-saving solution. One such rebate resulted in a negative 0.24-year payback, as the rebate was greater than the cost of the Hydromx fluid.