Is simply saying a that a chip is a fantasy chip enough? NO. A seller of an item (and this applies to any business transaction) is responsible for the reasonable interpretation of his representation. Generally the law looks at what is the normally accepted business practices, and who in the transaction had the greater knowledge.

The fact that a person mentions "fantasy chip" in their description could be interpreted in more than one way. An regular collector may know what is meant by fantasy chip, but it could mean that is is a highly desireable chip to a novice. THis can be further obfuscated by references such as "casino chip" or real casino names on the chip.

I've not seen the actual description, but I don't feel that hiding the fact it is a fantasy chip in the description is an honest representation of the nature of the item.