A company produces three joint products, A, B, and C, and generates scrap S from a common production process. The total joint production costs up to the split-off point are $500,000. The final sales values for products A, B, and C are $300,000, $150,000, and $100,000, respectively. Allocate the joint production costs to each product using the sales value at split-off method, considering the by-product and scrap.