He was very good last season and had a great end product (21 goals and 15 assists). From their strikers, only Messi played more than him and was more influential than him. I think that he comfortably outperformed Neymar.
However, they probably want to give more influence to Neymar and they also want Suarez, which means that most likely he would go to bench. Anyway, I doubt that 50m euro is true, unless there will be clubs going into a bidding far, he'll go for cheaper. 30-35m euro IMO. And worth every cent of it if we sign him.