Calculate the total price of books ordered by customer named Lucas Wyldbore.
total price refers to Sum(price); full name is composed of first name, last name
SELECT SUM(T1.price) FROM order_line AS T1 INNER JOIN cust_order AS T2 ON T2.order_id = T1.order_id INNER JOIN customer AS T3 ON T3.customer_id = T2.customer_id WHERE T3.first_name = 'Lucas' AND T3.last_name = 'Wyldbore'