Well I get charged 5 baht/kwh at my condo.
I have a 25.4kwh battery, a full charge consumes about 33.9kwh = 169 baht, that goes about 75km cruising on a highway.
With the ICE I get 5.5L/100km on the highway = 4.125L/75km = 142 baht.
Now I'm sure a real EV that didn't have to lug around an ICE with it can achieve a little better economy, and people living in houses can get cheaper electricity, but the real-world savings are still a little overstated.
But, in BKK there are heaps of free EV charging stations...