Before we discuss, we'd better understand what is expensive here:
If you keep this point in mind, you can easily find out what's more expensive and what's cheaper in Canada:
For those products require lots of labour during the manufactoring, such as clothing, hand-made stuff, you'd better bring them.
For those mainly consist of intellegent contents, such as book, CD(software), it's also expensive here too. Bring if necessary.
For those product imported, or the material imported, into China, you'd better forget it and buy them in Canada. These include cell phone, computer memory, cpu, tissue paper (most of the material is imported).
Further, for medicines...especially Chinese medicines, you'd better bring some ... who can tell me why they are cheap in China? :-)