What is somewhat unclear and may be related to the higher cost is the fact that the existing heater outlet is 30 amps. Does that mean that it has a 30 amp breaker in the panel? If that is the case, the wire size from the panel to the heater outlet may be #10, which is rated for 30 amps. 40 amps would require at least #8 wiring. Does the electrician have to re-run that cable? He does not state that in his short job description, but that may be implied.
Also, depending on the EVSE you get, there may not be any controls on the EVSE. My chargepoint has nothing that is used associated with daily charging. The charging cord is simply taken from the hanger and plugged into the car. Charging starts automatically. So you could use the 1.5 foot cord and plug the EVSE into the existing outlet, assuming the circuit supports 40 amps. Just get an EVSE that plugs into the existing outlet.
