They pay GST in Alberta 
Ah, yes, Alberta pays 5%, Ontario 13%.
The after tax price of a $100K Tesla is:
$105K in Alberta
$113K in Ontario, subtract $3K rebate = $110K
The after tax price on a reasonable spec Chevy Bolt is :
$52.5K in Alberta
$56.5K in Ontario, subtract $14K rebate = $42.5K
The after tax price on a reasonable spec Smart ED (with the usual dealer discount on these cars) is :
$25K in Alberta
$19K in Ontario ($3K tax)
Alberta car buyers get a goodly break on buying a Tesla Model X/S, and those in Ontario get a big break on a Bolt and Smart ED.
Over the life of the car, the benefit to Ontario having a public owned electric utility starts to pay back the rebate a bit.
Say 250,000 km driven over 10 years, 90% of the time charged in garage overnight, that's 63000 kWh.
Ontario sells excess Nuclear power for 3 cents per kWh, and over the next 10 years cost of production is 9 cents (raised from 6 cents today due to refurbishment, this rate increase is already approved).
So, Ontario nets 6 cents per kWh on 63000 kWh = $3780.
Therefore, the net cost of the rebate to Ontario is reduced by EV owners using up excess electricity normally sold for reduced price to the US.
In Ontario, the $8.5K rebate is effectively offset by ~$3.5K tax and $3.5 "bonus" electricity revenue.
Of course, now we would need to figure in fuel taxes on the other side, and that also would benefit the province, but of course, some of that tax is paid in health care costs due to the emissions of the cars.
It's a lot to try to factor in, I grant that, but I'm just demonstrating that there is more to this equation than "REBATES OMG!!".
Cheers.
