On Jet fuel, I only spend about $25 a month. On gas(not glow) I spend about the same amount. I don't do glow anymore. I don't do electric, but the batteries have a cycle limit, or number of flights. Take the cost of the battery divided by the cycles, and you will have a cost of per flight. If you are worried about fuel cost, as a beginner, you should worry more how many planes will you wreck to learn and their cost replacement. Get a simulator to cut that cost down. Get a worthy instructor too. Not all helpers at the field are good instructors, but they try.