You don't rate him - that's fine and it's you perogative. Van Gaal may not and may choose to go for other alternatives - again, fine. The fact is that's a matter of opinion, and to be honest not relevant to this debate.
The primary objective of a forum is to exchange opinions, or atleast that's what I've learnt so far. Whether Van Gaal rates him or not, is tangential to what Mane could add at United, which is the core point of contention here, especially considering his potential transfer fee.
The issue here is the facts that a lot of foreign players (from top internationals to average squad players) don't succeed in the Premier league for a myriad of reasons - not least how tough it is in comparison to other leagues. Therefore, I can understand why United (or any other big club) would part with more money for a player with a good grounding here, over and above a foreign player who hasn't played here. It mitigates risk and increases chances of success.
One could easily spin that around and list the Premier League players who proved to be bad investments for the top clubs. Folks fixate on the lesser talents that failed, but discount the likes of Suarez, De Gea, Aguero, Silva, Hazard, Kompany, Zabaleta - all of whom would probably make the Premier League XI for the past 5 seasons or so. Folks keep harping on the failures of imported players, but what about Carroll? What about Rodwell? What about Lovren, Lallana, Dembele? What about under-performers like Young and Fellaini? All players that a lot of United players wanted because they were proven in the league. Even Ings for that matter, who was being championed only a few months ago. There is no great mitigation of risk, when it comes to a club of United's scale.
The fact is United will overpay all over the world because clubs know they have huge sums of money. What they had to pay for Martial totally undermines your point that we will overpay here but not elsewhere.
Added to that Premier League clubs are having to pay a fortune for players anyway. The likes of Newcastle United routinely paying £15 million for players tells you what you need to know - the world and its wife knows that PL clubs are rich.
The fact is the more money in the game the more players will cost. Its happened for the last 100 years and if you decide as a club not to get engaged in that you'll fail because the best players will go elsewhere. Clubs are now full of "Directors of Football" and "performance Analysists" who know square route of bugger all about football, but think they can look at figures on a spreadsheet, play "Moneyball" and sign players who will do well who nobody has heard of. Aston Villa is a great example - a commitee of men who've failed elsewhere and one who used to work for Gatorade telling Tim Sherwood - a man with a lot more footballing experience which players he should buy. It's a joke.
Come on mate. The whole world knows Barcelona, Bayern, Madrid are loaded. But they are more methodical with how they spend that money. Not one of those clubs would spend £35 million on a player like Mane. Bayern got a superior player in Coman this summer for a £6 million initial loan, and if they buy him permanently from Juvetus, the total outlay will be £20 million. They also bought Douglas Costa for £21 million. Madrid bought Marco Asensio for £4 million. Those clubs reserve big fees for top talents, and for punts, they usually keep it in the £15-20 million range. Instead of buying a Mane and a Fellaini, they club the money together, and launch a bid for Bale.
United have the choice to not overpay for Mane, and instead plump up extra cash for someone like a Griezmann, who is arguably one of the Top 15 players in Europe, irrespective of position. United had the choice to dole out a few extra million for Aguero, Silva, Hazard but we instead plumped for Valencia, Young and co. because they were proven in the league. We delayed Ander's transfer by a season, and seemingly vetoed the deal for Thiago, because we wanted to activate the league proven Fellaini's buyout clause after its expiry date.
Our transfer dealings post Ronaldo have been quite poor compared to the Top 4-5 European teams, who have as much money as we do. The decline we find ourselves is in no small part because we opted to Premier League experience and sub-elite talent, while bigger talents were imported from other leagues. That needs addressing, we need to improve our dealings and our scouting system. We must stop overpaying for players who aren't top talents, because that's what helped land us in the current conundrum. We need a massive injection of quality still, not just improvement over what we have. No one is forcing them to overpay for Mane if they don't choose to, irrespective of how much money the club has.
When we sign players, whoever they are I want the manager to be able to get what he needs. If he feels he needs a player who can come in, hit the ground running and do well, and that player costs more money because he plays in the PL then I have no issue with it.
Fair enough. However, that doesn't mean we can't argue the merits/ demerits of said move. Just as we are within our rights to discuss his matchday, tactical, personnel decisions. The decision to sign a particular player isn't beyond reproach. And I for one strongly feel spending £35 million on Mane will prove to be a misguided decision considering the medium to long term. Just as I felt signing Benteke would've been a bad decision in the summer (open for discussion still depending on his performances for Liverpool).