I would not recommend the ones at Dollarama for more than bunny proofing. They are kind of flimsy and I would not trust them with a rabbit. The seem of the wire going around the edge is taped together.
I would suggest to keep looking on kijiji. It can be awhile to find them, especially at a good price, but it can work out. Garage sales can be good too, but it is hit and miss, especially if you don't go to them anyway. Second hand stores might get some in as well, but again it is hit and miss.
If you are looking for new ones, Bed Bath and Beyond is good. Get the 20% off coupon (sign up for the newsletter and you get one right away and then one every month or so). The regular price is about $25, so the coupon makes it about $20. There are 19 grids, so it works out to a bit more than $1 per grid. Other stores might put them on sale from time to time, so check websites and flyers. I won't pay much more than $1 per grid, so some sales are more than that.