I think you are seeing relic errors from the API data. Those cards are long gone, but sometimes the data doesn't update. For instance Scavo Chemist shows a price of $0.012 on the market, but the cheapest copy to buy is currently $0.135 over 10x the price shown on the aggregate view. This is a long standing issue with the market. PeakD it has to do with Splinterlands API dataset not updating in a timely manner, in some instances.