Windows [BUG] Profit Margin issues with fishing tackle

My family and I started a game and are playing on the highest difficulty setting because we really wanted a challenge. We noticed that an item that was really making us a good chunk of gold was dressed spinners, so we started hunting mummies for cloth, and then raising sheep for cloth. We finally figured out that dressed spinner's value wasn't decreased by the profit margin setting. Neither were treasure bobbers.
 
Top