I got curious so tried to add up the cost. I started from scratch a couple of years ago and found about this
Motor about $60
Hubin system
ESC 65
FM-9 timer 10
Jeti box 40 once edit as posts below, not the Jeti Box, but the FM-9 programmer for $75 if current.
KR system
ESC 50
timer 50
program 15 once
Lipo storage in fire safe box $20 – 30 on Amazon. Of course you may wish to spend more and get a large box. Cell phones and many tools and electric conveniences share those lithium batteries. Of course that will make the conveniences inconvenient.
Components other than batteries should last.
4 6S packs for 128.50 used for 500 flights so about 0.26/flight or per tank of fuel.
Recharge one pack 2 amps x 25.2v 100.8 watts or 400watts for 4 packs and with inefficiency, perhaps double. One 100w bulb for 8 hours... The cost of a kilowatt-hour of electricity varies across the country, but the average (including all charges) is about 15 cents.
Cost of motor and electronics, 150/500 about 0.30/flight or up to 0.33/flight if the higher option
So about 0.55/flight – 0.60/flight with the box
Charger costs vary and the chargers should last over years and many battery packs, so a bit more difficult to figure "in the tank costs." Of course those IC motors like batteries, glow plugs and other items as well. If fuel is about $20/gallon and you get 32 flights then about 0.60/tank and that doesn't include motor and initial costs. I haven't researched fuel costs and usage so may be off a bit.
What is the cost of building the plane if your time is worth 1.00/hr plus supplies? Is there really enough difference in IC and E to offset the overall costs, and the overall enjoyment, at least on some days, of the hobby