If you consider the cost of a round trip however the price gap is narrower but still more favorable than a combustion engine:
Supposing you take a 1'000 mile trip which requires 385 kWh, if you recharge your battery at a public station costing $0,50/kWh then you must spend a total of $192 for this journey compared to $225 for fuel (only 1,2 times more expensive).
