ricktoronto

Which is only fair. Someone wants to pay $500 for coach and bid $300 for an upgrade to a flight that would cost $1,200 otherwise.

WestJet says, "well, if you want $800 as the fare basis for WS dollars, spend $800 on a fare". What they are really saying is spend the whole $1,200 for the seat to begin with, because the $800 is still less than the full price of the ticket and therefore you are getting a discount, and should not earn a reward for getting a discount.

Airlines that award miles instead of dollars like WestJet does, don't give the higher miles (equal to WS$) based on COS if the passenger did not pay for the COS but was upgraded through their various methods of doing that including paid upgrades, miles or cash+miles.

So if you pay $500 to upgrade JFK-MIA on a coach ticket you earn coach ticket miles, not business class miles. Because you did not buy a business class fare. To be fair then the same rules apply on WS. You did not buy the class of service, you paid more than coach and less than full price and get a % of what the ticket cost.