Actually that was a pretty standard (or slightly less) price for those. There are just way too many to have them showing up all over the place. I think someone from the casino had racks of them, or at least, stacks.

Jenna operated casinos for Winnebago tribes. Ho-Chunk used defaced Jenna chips. Sands used defaced Jenna chips. They may have been used elsewhere since that tribe runs three casinos.