An interesting question.

It occurs to me that the ChipGuide does not provide a "Usage Statement" that would provide a clear answer to the question of ChipGuide image usage on eBay or for any other "commercial" purposes. I will look into that. However, the website and all of its contents are copyrighted, which would prevent use of the ChipGuide contents.

Practically, though, I think it is a poor practice to provide "generic" images of items for auction, unless they are new. The condition of a chip is important in determining value, so any images provided should be of the actual item to be auctioned.

You can, however, and I recommend providing a link to the item on the ChipGuide. That will provide more traffic for the ChipGuide and not be in violation of any laws.