A lot of the expenses in flying arise out of regulatory requirements. Want to carry passengers? Pilot needs a license that take several hundred hours minimum to obtain. Want to use a part in an airplane? Getting it through the FAA certificating process will inflate its cost by several multiples. Want to operate an aircraft? You need to get it inspected every $fixnum number of hours of operation by a mechanic who in turn has to do everything the 'certified' way and is himself certified by the FAA.

It's these costs, not fuel costs, that account for a big percentage of the cost of flying. There's no meaningful way to reduce the cost of flying without reducing them. Perhaps electrics will incur much lower costs in maintenance, reducing costs somehow.