Junte-se duas vezes.
SELECT s.name, p1.ProductName AS product_1_name, p1.ProductPrice AS product_1_price, p2.ProductName AS product_2_name, p2.ProductPrice AS product_2_price
FROM sponsers AS s
JOIN products AS p1 ON s.ProductID1 = p1.ProductID
JOIN products AS p2 ON s.ProductID2 = p2.ProductID
