It says
here that the price of topping up has gone up ("Mileage can be purchased at 4¢ CAD per mile, plus applicable taxes").
Is this just recent? Seems to me I only paid $.03 per point when I needed a couple of hundred to clean out my account when the dreaded change fee for awards tickets was announced.
Not much fanfare from AC over this, methinks.
No wonder they allow you to buy up to 30% of your required points.