Tesla focused its pricing on drivers of gasoline vehicles, and their gas cost savings estimates are actually quite low compared to the real savings you will achieve. It was annoying when you already drive an EV and are buying a Tesla though to have to uncheck the savings option to see the pre savings prices. They changed it now so by default it only includes the $7500 and no longer automatically checks the gas savings.
EV (133mpge) 0.045 cents per mile (Tesla Model 3 SR+ RWD)
Gas (26mpg) 0.155 cents per mile (Subaru crosstrek)
Based on my experience I highly recommend everyone buy any EV if you drive an ICE vehicle. Even charging at DC fast chargers still saves money, but if you can charge at home, you are really missing out on savings big time and it's time to look seriously into it.