I had to do some repairs to the bike a few years ago, and my dad told me about a great place to get stuff for it....wholesaler type place, but would sell to people too.
I got the fiberglass resin, the catalyst (can't think of the proper term...mix it in so it hardens), bondo/putty, and the catalyst for that, for (what I thought) was good price.
I probably paid the same as what Canadian tire wanted, but I got two or three times as much.
(didn't use much either, so the "deal" part is subjective...but I have it for future work, as required)
I might still have the receipt, I'll check when I get home....if not I'll check with my dad to see if he remembers.
Edit: My dad was online so I asked him, we figure it was this place:
Advanced Auto Color & Bodyshop Supplies