This research put forth exergy-based economic and sustainability analyses of a (J85-GE-5H) military turbojet engine (TJE). Firstly, sustainability, conventional exergoeconomic and advanced exergoeconomic cost analyses were executed utilizing kerosene fuel according to real engine working circumstances. The engine was likewise investigated parametrically, considering H(2)fuel utilization. The sustainable economic analysis assessment of the TJE was finally actualized by comparing the acquired outcomes for both fuels. The entire engine's unit exergy cost of product(cPr)with kerosene was determined 76.45 $/GJ for the military (MIL) process mode (PM), whereas it was computed 94.97 $/GJ for the afterburner (AB) PM. Given the use of H-2, thecPrincreased to 179 and 288 $/GJ for the aforementioned two modes, seriatim. While the sustainability cost index (SCI) values were obtained 52.86 and 78.84 $/GJ for the MIL and AB PM, seriatim, they became 128 and 244 $/GJ when considering H-2. Consequently, the higher exergy demolitions occurring in the afterburner exhaust duct (ABED) and combustion chamber (CC) sections led to higher exergy destruction costs in the TJE. However, the engine worked less cost efficient with H(2)fuel rather than JP-8 fuel because of the higher cost value of fuel.