Costs of electric:
Small electric planes are quite affordable, planes that traditionally were flown with .15 or smaller glow engines use 3 cell lipos that can be charged up with cheap chargers. You can even own a couple of these chargers and have a couple of batteries charging while you're flying. Three cell 2100 mah lipos go for about $80 bucks each, most of us have no problem owning three or four.

On the other hand, if you want to fly electric with planes that were traditionally powered by .60 glow engines, it starts to become stupid-expensive. Now your looking at 6 cell 4500 mah lipos that cost about $280 each. You can't charge these with inexpensive chargers. A charger that will charge these batteries costs about $200. Use your car battery to recharge these batteries and your car might not start after a day of flying so you will also want a power supply that plugs into 115 volts.

On the other hand, once you own a charger and battery packs for a .60 size plane, you can easily build a second, third, or a whole fleet of them and you won't have to re-buy the charger or battery packs.