I pay a nominal 21¢/kWh at home (including TDSP charges), but I also have "free nights" and I have shifted the vast majority of my usage (stovetop, oven, clothes dryer, dishwasher) to the free hours. I can't really shift air conditioning, but I use free night hours with the thermostat set to 70° so that the A/C doesn't come on as much during the day. The 4 kW of solar panels on my roof also help with the A/C during the day (but I have to choose between free nights or net metering). The actual price paid per kWh last month was under 5¢. So, if I really needed a charge away from home, I'd arbitrarily cap it $2 (the owner does have to pay for maintenance and property tax, after all) plus actual electric cost. Given I know damn well how competitive the electricity market is around here (central and north Texas), I am absolutely not willing pay any higher than 10¢/kWh away from home.