A jewelry supply house incurred $300,000 in factory overhead cost, of which $50,000 was identified as the cost of sanders for polishing tool bits. It also incurred rent of $75,000 for the building in which the tool bits and other products were manufactured. 20% of the building space is used to manufacture tool bits. It paid $100,000 in sales commission for tool bits. Under activity-based costing, the jeweler will identify ________ as product cost for tool bits..