Those are 2 strokes, it isn't about the money so much as it is the 4 stroke sound and suitability. That said, when there were no 30-40cc 4 stroke model airplane specific gassers the Hondas and Stihls were available, then Fuji sold a less capable 4 stroke engine for 3~4x the price of the Hondas so why pay more for less? But the goal is a 4 stroke gasser.