For people in southern Ontario and the GTA particularly, the DRAS Annual auction will be held on Sunday April 15, 2012. This year there is no show, but a vendor area and conservation display. The auction is a a "buck a bag" for vendors and is open to everyone. This year a $2 admission fee for those over 10 is being implemented. This is a big auction with usually 1000+ items, and no used dry goods.
More info at Durham Region Aquarium Society - The Front Page
. Read the PDF for full details and forms.