@NJM78
You are forgetting two things, first the unwillingness of a club to sell his player. And secondly the fact that Van Gaal wants specialists which means that the pool of players we can be interested in is much smaller.
We are in a "Barcelona situation" only 4 or 5 player can interest us, if you want a left footed cb who is good on the ball there is Vermaelen, Laporte and Inigo Martinez, and not much more, the two spanish boys cost 35m, that's a lot of money and almost 20m more than Vermaelen.
For the midfield some players didn't want to come (Kroos and Rakitic), the others their clubs don't want to loose them. For Vidal we need to wait for medical and financial reasons.
For the Winger/Wingback, Van Gaal seems to want a polyvalent player, a specialist of the wing not an inside forward or someting like that, so no Depay, Pedro, Sanchez, etc... But players like Cuadrado or Di Maria.
And all that according to Van Gaal schedule, can only happen after he assessed the team which include knowing Januzaj and Fellaini. What is happening right know was always going to happen under Van Gaal because that's how he works.