The only way Pogba will still be worth 70m in a few seasons is if he has a monster season. As I said, way better than the rest in the world at his position.
Don't get me wrong, I like Pogba and he's a good player but the 70-80m price tag is bananas. That is almost Ronaldo to Real territory.
And at the end of the day, who are we losing really? United lost worlds best player, Tottenham lost their best player, Inter when they sold Ibra lost their best player and so did Juve more than 10 years ago with Zidane. This time we'll lose Pogba who could very well be replaced by Marchisio and Asamoah + whatever really good investments Marotta could make with 70m. I think it would have a more negative effect on us if we lost Vidal instead. But really, this Juventus has no player it relies on too much.
Just think it will be an oppurtunity lost.