The reason why some Canadian customers pay varying amounts for their subscriptions is because of provincial tax and shipping.
For example, in Ontario the Snack box would be $22.95 + $9.00s&h + 13% Tax ($4.15) = $36.10 CAD. Provincial tax is between 5% and 15% depending on the province. It is shown at checkout before you complete your purchase.
If you think you've been over-charged, please check your provincial tax rates. If you're still not sure, please reach out to us as firstname.lastname@example.org. We'll be happy to help you out.
Here is a list of taxes broken down by province.