I bought 7 kilos Canadian at auction last winter and spend - well a few weeks - sorting. What I pulled out were the specially nice commemoratives - just one or two of each - stamps that had known varities - and stamps that I could lot on eBay
(I pulled out .5 kilo of foreign that sold well). When I had extracted all that I wanted I sold the rest on eBay
in kilo lots and made about $100 on the deal.