Barca have sold Aubameyang to Chelsea in about 15 million deal,and gave Marcos Alonso as part of the deal.It is pretty fair because they wanted Aubameyang by all means since they are not getting the number of goals they required.He is brought to be a messiah to the club.So far,it's only Sterling  that has been doing so much on the field,contributing and scoring goals as well.
Aubameyang helped them get to second on their league  table which shows that his goal contribution has delivered good hope on the entire team.