There's many different ways to put a value on Supercharging. During a three-year period:
1. Electricity Savings. If a person uses the SC as a substitute for home charging for 20% of miles driven (3 x 3000 miles/year = 9000 miles): For 3.2 MW at $0.15/kWhr = $480.00
2. Gasoline Savings. Use of a SC may open up long distance trips that may be inconvenient without it. Assuming use of 20mpg gasoline vehicle for one 300 mile trip/month. (36 x 300 miles = 10800 miles at $4.50/gal) 10800 / 20 x $4.50 = $2,430
3. 50/50 Combination of the above. ($2430+$480)/2 = $1455
4. Rental car offset. If you only own EVs and need a rental car for the occasional long trips: 36 trips x 2 days x $50/day rental car = $3,600
Now to account for the expected added resale value after three years which, with the exception of Alaska & Hawaii, should be more or less a national average. This is a rough guess, but having a SC may add between $600 and $1400 to the resale value. If the SC holds value on par with the rest of the car...43% x $2000 = $860. I think this would be a conservative number - the actual should be higher.
Adding the "Combo" savings to the added resale value gets you: $1455 + $860 = $2315. This is close enough to the added cost of a SC to make it a worthwhile investment, assuming that you plan to actually use a SC. If you have little or marginal use from it because of your driving habits or where you live, SC = probably a bad investment. However, if you can and will use even just occasionally, the SC is probably going to be worthwhile for you.