The online community of knife collectors, A Knife Family Forged in Steel
Matthew, have you tried typing any of these names into eBay? Obviously the Spydercos are going to have increased in value more than the Gerber Gator, but regardless, I'd start on eBay...
Matthew, I recommend that you go to ebay and try to find these. You may luck out and find some values as stated in ebay. Good Luck !!!!!
Highlight just the name of each knife on your list, right click on it, hit "search google for..." and check out what comes up. Many knife stores, forums etc will show up and allow you to get a more accurate average in your pricing, as yes...eBay can be all over the place.