In my case, thanks to the solar panels on my roof, I pay a fixed price for electricity except for those EXTREMELY hot summers when I run my air conditioner more than usual. Charging my Zero doesn't even put a dent in the electricity I use vs. electricity I put back into the grid. Plus, most of the public L2 charging stations around here are free (including the stations installed at my office by my company; the ones I use the most as I use the Zero for commuting). Those places that do have an associated cost are still WAY cheaper "per mile" than gasoline, even in my 70mpg XMAX (which, unfortunately, does require 91 Octane minimum).
Contributing to the cost is also the far less maintenance required on the Zero compared to my Yamaha and BMW. In fact, by riding the Zero more often than the other two means I'm putting far less wear and tear on them so they don't have to go in for service as often.
Yes, I do own a car. I use it primarily on those days I'd have to be out of my ever-lovin' mind to be on two wheels. I bought it brand new in the late winter of 2018 and it still has less than 19,000 miles on the odometer.