Calculate the average budget of the movies directed by Jaume Collet-Serra.
directed by refers to job = 'Director'; average budget = AVG(budget)
SELECT CAST(SUM(T1.budget) AS REAL) / COUNT(T1.movie_id) FROM movie AS T1 INNER JOIN movie_crew AS T2 ON T1.movie_id = T2.movie_id INNER JOIN person AS T3 ON T2.person_id = T3.person_id WHERE T3.person_name = 'Jaume Collet-Serra' AND T2.job = 'Director'