What return on sales (percent markup) will Jim be receiving?

Jim has a patent on a device to aid in blood circulation. To have the product made in China, it will cost him $50,000 for set-up (fixed costs) and $150 per unit (variable costs) given an order quantity of 1,000. Jim has a commitment from a large retail chain to purchase all 1,000 units for $300 each. What return on sales (percent markup) will Jim be receiving?