Depending on the glow engine type you pick you should be able to keep your fuel cost down under 20$ a gallon. I was paying 17 a gal for 15% in my 2 stroke and could of got away with 10%. I just switched to 30% heli for my new 4 stroke that is 34$ a gal [:@] Not all 4 strokes need expensive fuel though and for the cub your looking at even if you went with a 4 stroke there is no need to get one that needs high nitro fuel.