If we examine our signings since Pep took over, and divide them in expensive (+20£), medium (10-20£) and cheap (-10£) this is our (subjective, obviously) success rate:
Expensive: 2 failures (Chygrinskiy, Zlatan), 2 successes (Villa, Alves).
Medium: 3 failures (Keirrison, Hleb, Caceres), 3...