Electricity rates in some parts of California run up to $0.50/KW. But you can get EV rates, or Time of Use rates that are considerably lower ($0.20 or less). And gas can run up to $4/gal for the 92 octane required/recommended for most vehicles that are even remotely close to a Tesla's performance
Yeah, I know it's high there, but even at $0.50/kWh, on a full 100 kWh charge with losses (eg 110 kWh from the wall), that's $55 for 300 miles. A Q7 averages 19 MPG and requires premium fuel. Currently lowest price is $3.43 on Gasbuddy in Ventura. $3.43 * (300/19) = $54.15.
That's an absolute worst-case scenario. With any reasonable rates (eg an EV or ToU rate), the X costs less than half what the Q7 does for fuel.