Resale appraisal guilds like Blue Book and VREF establish average market values based on an aircraft having mid-time engines. If an aircraft is close to overhaul, its value goes down significantly. For aircraft with hours less than mid-time, value increases. TBO’s STC provides 2000 hours of time, added back to the value of the aircraft. Unfortunately at the high cost of overhaul, an operator will never recover the money paid in for a traditional overhaul, at a resale event. However, the TBO Extension costs about half of the value you will add back for mid-time engines. So, it pays for itself and earns you money.