We'll need to agree to disagree on that one. Carroll had scored 6 goals in his previous 3 EPL seasons combined before joining West Ham, and a grand total of 20 EPL goals in his 7 season EPL career.
That proved to be a good predictor of his goal scoring form and his injury record. After West Ham forked out the £15 million, he played another 6 seasons for them scoring 26 goals total (never reaching double figures in any season and only making more than 20 apperances in 1 out of those 6).