Regardless, I do not think he has shown the type of performance that would be adequate to earn him a transfer fee of $13 million, no matter what.
Andrey Santosis a central midfielder with 8 goals for club last year and we don't have any midfielder capable of scoring or assisting goals apart from Mount which have been off form lately. He's also a Brazilian and we know how good this players play when they get sign into a top Europe club. I also think the fee was decent. Chelsea is a top club and you don't expect other clubs to sell their players very cheap to us when they know we can afford any price they give and we're desperate.
I have seen him play. I absolutely do not think that he is some wonder kid who is going to do something impossible for Chelsea. Some people just see a kid play well these days and start throwing money to get him in the team. I do not believe that he is worth the money that Chelsea gave for him. If this was around 8-10 million, I think even that would have made sense. But 13 million is too much.
Now that football is seen as a business, it is now considered very normal to give such money to young players who are a little promising. These funds could be transferred well 10 years ago, but now they are seen as "simple money at risk". If the player does not meet the expectations, the team can be very upset. Chelsea is a great team. I think they can bring more important young people to the youth academy.