Yes, and not much.
120V charging is around 80% efficient, while 240 is a bit over 90%. The difference is that the car is kept awake for the duration of the charge event, and takes like 250W or somesuch. That's a decent amount of overhead on a charge session that's got maybe 1440 watts. Its less of an overhead on 240, and the duration of the charge is half or less, depending on the current of the 240V circuit.
If you don't need it, don't get it. Even the cheapest electrician-installed outlet will be $200 or much more, depending on the distance to the panel. Heck, even the GFCI for a 14-50 will run you $100-$150.