I (and am sure there are so many fans out there) am sick and tired of hearing these kind of spending prospect. Like you said you and some Joe Blow can make a team top four with that amount of money to spend! People keep talking about how Fergie had left a team without signing big names for years etc... It is the manager who can make use of what they have and who they have and get them to play to their strengths and play as an attacking team which also has the required passion and motivation to play to win for the club. That's what Fergie and United has always been about.
United is not a spending club regardless. People need to get a grip.
Ferguson did well on a lower net spend after the Glazers took over however by that point the man was the most experienced manager in the league, he had mastered winning that competition, he knew exactly what needed to be done and he did it and furthermore he had a lot of experience in his dressing room, Evra, Ferdinand, Vidic, Scholes, Giggs and more, he had players who had mastered winning the premier league!
Had Mourinho, Ancelotti or Guardiola, a top manager like that the drive to stay at one club and so that level of experience in a league, I think they also could operate after 20 years on a lower net spend than they had previously.
As for Ferguson let's not pretend we weren't amongst the biggest spenders in the premier league prior to the glazers and even after he lost the title to City on goal difference he spent £63m in total and £51m net.
The board seem to want a dominant club both domestically and in europe, they probably feel this will help them maximise profit. They think the best way to go about that is to build a team with an identity independent of the manager which can be easily continued after the manager leaves even without a top top manager, both Bayern and Barcelona are examples of how the manager only needs to continue what is already in place.
Your approach is fine but it is reliant on finding and attracting that excellent manager that has the ability to make the most of what he has at his disposal but without that excellent manager we might not be challenging domestically nevermind in Europe.
When Louis van Gaal leaves, if he does build the foundation he has been tasked with building there are quite a number of managers who play a similar style of football that could come in, continue his work and we will be very successful.
The board have made their decision and I'm happy supporting them in that instead of clinging to the past. If you don't change with change you'll be left behind, I think the board have made a sensible decision.