If I were United, as much as this would be a foreign concept to them given the last 30 years, I would shelve any title or cup ambitions for a season or two and get back to building a solid base. The ghosts of their past success are killing their team. It's not the 90's or 00's anymore and they are a million miles away from being there. Forget the past, take your medicine, focus on hungry players that aren't there for the money but are there to prove themselves. Start doing what United used...
If he was an established striker I think it would be more reasonable, but given he's just a prospect, it's unlikely he'll start many games and so you'd have to ask if it was worth it on another project player.
Credit to United, they didn't dump 60 mill on him like they did with Rasmus. Maybe they are learning.