The BEST place to buy chips would be to advertise in a "trade" magazine. If you want to tap into a group that has some chips, place an ad asking to buy a single chip or an entire collection in a "trade" magazine.

Place an ad in the Las Vegas, Atlantic City, Deadwood newspaper (or the area you collect). If you collect illegals from Jeffersonville, IN, place an ad in their local newspaper.

The key is to buy from someone who doesn't sell on eBay and doesn't collect chips. Make a flyer and place it at your local flea markets, antique shows, antique stores, etc. Make a shirt that says "I collect Casino Chips" and wear it to flea markets, antique shows, yard sales, etc.

IT WORKS!