I'm with
@abrandt on this one. Although I could do all the work myself, bypassing the 2nd click of the heels on my ruby red slippers, There's still the $500 material cost to get that 240 outlet into my garage. Driving an average of 250 miles per week, I can easily get 100% charged each day even if I use the schedule to do it between 21:00 and 9:00. I do drive twice as far on Thursdays than on other days, so sometimes Friday morning sees 95-98%, but I easily catch back up to 100% on Saturday morning. Considering my cost for electricity, I can drive two years for what the upgrade would cost.
If I put on the miles like
@Aquavir, it would be a no-brainer. But for now, 120V will do just fine.