Can’t see this one happening.
A case of needs meeting demand.
I think it will happen:
1. There is a relationship between the two so there is trust.
2. Barca is open to selling Frenkie -- so he must know that he ain't their top dog there and isn't indispensable. That's never a good feeling for a player that the shoe could fall off anytime. If may not this summer, maybe next ... but this summer at least he trusts who he will be playing for.
3. ETH sees him as the building block or foundational player for the way he wants United should play going forward. He needs to put the pieces together but needs to start with his base. It may blow the budget but then if he is that critical, he will have to make his priorities and get other pieces next summer.
4. United's management knows Barca desperately need the money to bring in Lewandowski to form that vaunted Dad's Army Twin striking force with Abba. And being the 1st ETH window, and a new management approach, they cant not support ETH.
It will be ETH's decision to pull the plug and not his bosses. He will need to decide how much that cost will be at the sacrifice of not getting other needs, this summer.