Check out this collection on Ebay: (This isnt my auction btw)

Advanced Squad Leader (ASL) - Avalon Hill / MMP - eBay (item 200281969217 end time Dec-14-08 21:00:00 PST)

That's a lot of ASL stuff, many of it in new condition! I think its very rare to see something like this. Don't know what the price is going to be though, its currently at almost $2000 with 3 days left and reserve not having been met yet.

This is from the Wikipedia entry for Advanced Squadron Leader, for those who don't know this game:

Advanced Squad Leader (ASL) is a tactical-level board wargame that simulates actions of approximately company or battalion size in World War II. It is a detailed game system for two or more players (with solitaire play also possible). Components include the ASL Rulebook and various games called modules. ASL modules provide the standard equipment for playing ASL, including geomorphic mapboards and counters. The mapboards are divided into hexagons to regulate fire and movement, and depict generic terrain that can represent different historical locations. The counters are cardboard pieces that depict squads of soldiers, crews, individual leaders, support weapons, heavy weapons, and vehicles.
Advanced Squad Leader - Wikipedia, the free encyclopedia