Tesla Offers $30 Monthly Home-Charging Plan for People in Windy Texas (businessinsider.com)

Based on consumption in my garage: if its 1 car, it's about $0.10 / kWh. If it's for all your garage's electric cars, say, 2, then about $0.05 / kWh. Not bad. Of course, there is a ~$0.05 / kWh TDU flat fee, which would be added to that.