Can you list the product ids and the booked amounts?
select t1.product_id, t2.booked_amount from products_for_hire as t1 join products_booked as t2 on t1.product_id = t2.product_id
What product ids are never booked with amount higher than 200?
select product_id from products_for_hire where product_id not in ( select product_id from products_booked where booked_amount > 200 )