I don't think he's coming to United after all. There are more attractive clubs that can pay him better and help him win more trophies, if he wishes to leave Villa.
We should have gone all-out for him before the season started. The Sancho obsession (?) plus our usual transfer-market inertia ruined what would have been one of our best signings in years.
Firstly, quit with your pessimistic bullshit in the first paragraph. You read like some troll-bot on Twitter! United can pay him just as well, if not better, than any club in the world. No team can guarantee you trophies long term, especially at the moment in the PL.
Secondly, we probably would have signed him over VdB, but after Villa stayed up they would have wanted around £80mil, even before his form this season. Seeing as we already have Rashford and Fernandes in his best positions, that outlay would have not made sense. This is why we chased Sancho so hard, he plays in a position at actually need a starting talent. I'm sure Grealish could play on the right, but it's kind of like buying a Ferrari to take the kids to school and do the shopping, it's not going to get the best what it's made for.
Grealish is turning into a great player, and might well leave for a bigger club for a lot of money, but I personally think you'll see plenty more young players of his level coming through that you can get before they break the bank.