SELECT distinct product.model, pc.price
FROM product
INNER JOIN PC ON product.model=PC.model
WHERE maker like 'B'
UNION
SELECT distinct product.model, laptop.price
FROM product
INNER JOIN laptop ON product.model=laptop.model
WHERE maker like 'B'
UNION
SELECT distinct product.model, printer.price
FROM product
INNER JOIN printer ON product.model=printer.model
WHERE maker like 'B'