Among the cars with an engine displacement of no less than 400 cubic millimeter, how many cars cost at least 30,000?
engine displacement of no less than 400 cubic millimeter refers to displacement > 400; cost at least 30,000 refers to price > 30000
SELECT COUNT(*) FROM data AS T1 INNER JOIN price AS T2 ON T1.ID = T2.ID WHERE T1.displacement > 400 AND T2.price > 30000