I agree. Yeah, our panel was right on the other side of the garage wall where the outlet was installed. We could've got our handy man to install it for $100 bucks (and materials), but we wanted a "licensed" electrician to do this, just for resell justification.$350 to run a 240VNEMA 14-50 outlet is probably right if it's close to the box. Your service box probably is very close to the garage. And you had enough capacity in your box. My friends had to add breakers, run pipe and the 220V outlet the Tesla fast charger plugs into. The Charger was a additional $500 from Tesla. Has wifi and some other features.
Personally any electrical work is part of the house if I were to sell. I can see someone wanting to take the Tesla charger with them when they moved. Kind of like taking a window A/C unit or something. Would I make a big deal out of leaving or keeping a charger if the buyer wanted it? Nope. They can have it if that was the hold up with the sale.