Using the average cost of electricity in the US as about $0.12 per kilowatt-hour, $3 of electricity is 25KHh, close to the value that Diver 300 estimated. So I would think a reasonable estimate of the energy to recharge the battery is about 25KWh. That's comparable to the average household daily electricity use.
Of course, that amount for the car would be for charging a totally discharged battery. If you only partially discharged the battery then it would take correspondingly less to recharge it.