It's about $4 per charge, at 7cents per kWh... Comes out to $250/yr. I guess they should include it if you live in HI or somewhere else with high-priced electricity, but realistically it is much, much less than, say, sales tax, which they also don't include.
Where do you live that electricity is actually 7c/kWh? I didn't really pay attention to my power bills until I moved to Florida, but down here, the real price is 14-17c/kWh; the actual kWhs are quoted as something like 7c but then they add a 7c/kWh fuel surcharge and additional fees after you cross certain usage thresholds.
My uncle in Wesley Chapel (Tampa) is paying ~7 cents/kwh from their local coop, I pay as low as 1 cent a kwh for 6-12 hours a day from Exelon's nuclear power in Northern Illinois.
On the bottom of the page they state their assumptions. $0.12 per KWH of electricity and $3.90 for a gallon of gas. However I think the price should reflect immediate savings and the gas savings should figure in total cost of ownership.
Which is even more incorrect given the current cost of gas ($2.09 in SC at the moment for regular). Which is not to say it won't go back up, but I just find it quite the sleazy sales tactic.
It'd be like selling someone a gun and saying, "it's free after you go kill your own deer, you'll never have to buy meat from a grocery store ever again! (but you have to pay $700 up front)."
This type of sales tactic makes me want to buy the product even less, not more, because it makes me wonder what else they're lying to me about.
That being said, it's good to see the prices coming down.