I picked up quite a few of them over the weekend at a local swap meet.

Did you pick up a handful, a box of one-hundred or boxes of them?

Most likely since the chips are an "unidentified chip" you are talking from 25 - 50 cents (in huge quantities) or a few dollars if you only picked up a handful. (this is also based on how quick you want to liquidate the chips and if you do it on eBay vs. other sources of selling).