Market / Craft Fair Fee on Schedule C

You could put the craft fair fee in Other Rent. The fee is for renting the space. But everything doesn't have to fit into one of the predefined categories. After the expense categories there is a place to enter miscellaneous expenses with a description. You could enter it there and call it "Craft fair fee."

Exactly where you find the miscellaneous expenses depends on what version of TurboTax you are using, which you didn't indicate.

Sounds to me like rent you paid to utilize the space. Perfectly valid business expense. Typically, when you can't seem to fit an expense into a pre-defined category, you just enter it as a miscellaneous expense. But if I recall, the SCH E does have a spot for rents paid, which is line 20 of that form.