He's been immense for Roma, absolutely awesome all season. His shot stopping is unreal, his decision making is first class and his distribution is every bit as good as Ederson's. Goalkeepers who posses this now, in this day and age of football will always command big fees, because their a sort after animal. More and more coaches want this, it's becoming the new sweeper keeper all over again.
Ederson wasn't the first choice because Tite probably witnessed the season Alisson had, were he came under fire much more than Ederson did and was first class. Whilst you don't see it, had you watched Roma in Serie A last season you would of, he's an absolute elite goalkeeper and rightly commanding the price being talked about.