Sometimes it seems like they had a great master plan!
Make their venue cheap and effective for the small seller until they became the 500 lb gorilla in the room, at which point they could keep raising their fees while providing less because they had ultimately created a situation in which they were the only game in town.
The advice now is go somewhere else! Create your own website! What you can certainly do and save the fees but they have made it so that it's almost impossible to get anybody to show up. It is not easy for an individual operator to compete with a marketing department with 500 full-time workers.