LF: Cheap tonner refill for Canon IP1600

[udh]

I have never done tonner refill before and need to refill the tonner for my Canon IP 1600.

1) Where is the cheapest (and reliable) place in GTA (preferred in Mississauga)?

2)Would it be cheaper to buy a self-refill package from ebay? Is it easy enough for a newbie?

The color is still half-filled but black ink is low. Do I need to refill both?

Thanks!