Almost freeCall it $4 a gallon for the fuel for a gasser oil included. I can get 14 flights out of a gallon or 3.5 hours in the air. (15 minutes each).
So $4 for 3.5 hours. For a same size nitro machine burning 30% fuel at $25 a gallon, they can usually get 6 flights per gallon. About 10 minutes each (and that's generous), they pay $25 for 1 hour flight -- big difference!
But you're right, gasser fuel is not free, its just cheaper. Cost is minimal comparitively but just think of it as savings per flight and then you'll get the idea: 6 nitro flights 1 hr airtime or $25 cost of operation. 4 gasser flights = 1 hr airtime. Cost is 4/14*4 = $1.15 or savings of $23.85 per hour of enjoyment. Adds up quick for the rainy day!
But yes Shuttlepilot, if you are not as experienced or have a tendancy to crash often, gassers may not be the best choice. Most people learn on a 30 size nitro and then make the move to a gasser once they are confident in their flying skills. Some however money is no object and start with gassers. I guess it varies from person to person. I personally started with a Concept 30 in 1991 and crashed it more often than I remember. Then in 1997 I graduated all the way to a gasser as nitro fuel was costing me alot back then even with a 30 and my calculations of a 60 size indicated its not worth it for me. Was so impressed and happy with my 1005 gasser back then I sold all my nitros (planes) and upgraded to gas powered planes as well. Now 2041 heli gasser flights later, I know I made the perfect decision back then!
MA 1005 Hanson 280, 4174 flts
Spectra 27 3DMax, 3242 flts
Whiplash V1-2 Hanson 300, 1492 flts
Whiplash V2 Hanson 300, 282 flts