SELECT avg(T3.cost) FROM physician AS T1 JOIN trained_in AS T2 ON T1.employeeid  =  T2.physician JOIN procedures AS T3 ON T3.code  =  T2.treatment WHERE T1.name  =  "John Wen"
What is the average cost of procedures that physician John Wen was trained in?
SELECT avg ( T3.cost ) FROM physician AS T1 JOIN trained_in AS T2 ON T1.employeeid = T2.physician JOIN procedures AS T3 ON T3.code = T2.treatment WHERE T1.name = `` John Wen ''
select avg ( t3 . cost ) from physician as t1 join trained_in as t2 on t1 . employeeid = t2 . physician join procedures as t3 on t3 . code = t2 . treatment where t1 . name = value
What is the average cost of procedures that physician John Wen was trained in ?