If you let a Nissan Leaf draw down to half charge, and assume a conservative estimate for the circuit's charging efficiency, it costs somewhere around $2.50 to top it back off to full charge.

Given the stated range of 100mi/full charge, assuming a linear relationship between % charge and range (probably the weakest spot in my logic here), half-charge probably gets me (& my driving style) about 30 miles. Which equals out to about $0.08 per mile.

My truck, with a 21 gallon tank, about 15 mpg in the summer, and a city range of about 315 miles, costs approximately $0.28 per mile if gas is $4.15/gallon.

If I consider only the cost of fuel (nevermind maintenance, insurance, and all that jazz), and I don't sell my truck, and make the Leaf my primary driver when the roads allow it, I would have to drive 150,000 miles to recoup the cost of buying a Leaf.

I've had my truck almost 5 years and I've only driven 44,000 miles.

It was a fun thought.