When I lived in Illinois about 4 years ago, I guy I worked with always said "You could fall into a pile of chit and come out smelling like a bed of roses" when it came to the great comics I was able to find. And my response to him was always "No, I WORK at it!" I constantly am checking eBay, other online auctions, craigslist, garage sales, flea markets, estate sales, antique malls, etc. looking for comics and certain magazines.
So just keep pounding the pavement (and the internet) and keep your eyes peeled. There are still many treasures out there to be had. (thumbs u