Aklıma ilk geldiği şekilde yazmaya çalıştım daha kolayı vardır belki ama, işinizi görebilir hocam
SELECT productId,( (SELECT count(*) FROM `soldProducts` GROUP BY product ORDER BY count(*) DESC LIMIT 1) * (SELECT price FROM `productInformation` WHERE productInformationID = (SELECT productInformationID FROM `product` WHERE productId = (SELECT product FROM `soldProducts` GROUP BY product ORDER BY count(*) DESC LIMIT 1) LIMIT 1)) ) as toplamSatis FROM product LIMIT 1