US amex SPG is going up to 95 USD (123 cad) annual fee, but with waived forex fees (common down south, not so much in Canada)
Earnings rate for US SPG amex is 1 USD:1 SPG
Earnings rate for Canadian SPG amex is 1 cad (0.77 USD):1 SPG
The gap isn't as big as it used to be when the cad was at par