If you want to talk about the cost of operating a turbine vs operating an EDF of equivqlent thrust. here's something for you to think about. It cost $1030 dollars for a set of 14 cell 7700 mAh Thunder Power high end 65C batteries. These batteries power a fan that has the same amount of thrust as a P-120. I can get 200 flights on these batteris so it cost me $5.15 per flight. A P-120 will need at least a 1/2 gallon of fuel per flight. A 5 gallon can of kerosene and oil cost about $60 and this will give you 10 flights. To spend $1030 on kerosene and oil you will need to buy 17 five gallon cans and you will get 170 flights at a cost of $6.05 per flight. So, it is actually cheaper to fly an EDF and you would also get 30 more flights for the same $1030 spent.I did not include the extra cost of a pipe, fuel tanks, and the 25 hour maintenance cost of the turbine (no 25 maintnenace cost for EDFs).