Bruce Corporation makes four products in a single facility. These products have the following unit product costs: Additional data concerning these products are listed below. The grinding machines are potentially the constraint in the product on facility. A total of 74.700 minutes are available per month on these machines. Direct labor is a variable cost in this company. Up to how much should the company be willing to pay for one additional minute of grinding machine time if the company has made the best use of the existing grinding machine capacity? (Round your intermediate calculations to 2 decimal places.)