Hi John
I know this is a bit late, but something you might want to check out is the Photographic Historical Society of Canada is having an auction tomorrow.
http://www.phsc.ca/
There's no guaranty that there will be an 8X10 there, but Ive seen many in the past. Last fall they had an auction where I got a Deardorff V8 with an 8X10 back, 4X5 reducing back and a 19 Artar for $850 CDN. The Artar wasnt pristine; the coating had a couple of marks. The Deardorff was in great shape. At past auctions Ive saw a Calumet with a lens go unsold for $900 CDN. Theyre spring fare is a good place to find some bargains as well. I sold my first 8X10 there. A B&J, not mint by any means but useable for $275 CDN. Good luck in your search.
Michael