According to transfer expert Duncan Castles, Leicester value Maguire at the same level as Dutchman Van Dijk.
The 27-year-old swapped Southampton for Liverpool in January and now United want to bring in their own big-money defender.
However, Leicester’s lofty demands could put pay to a deal with back-up targets Toby Alderweireld and Yerry Mina also on their radar.
“From what I’m told, the pricing, if there is to be a price for him, will be £75m – they value him at the same level as Virgil van Dijk,” Castles told the Transfer Window podcast.
“That should probably give you an indication about why Jose Mourinho is reluctant to go down that route.
“It’ll affect Everton, they’ve gone a long way in negotiations with Barcelona for Mina who they want to sign.
“If they don’t get him they’ll have to move elsewhere, and interestingly one of their targets is Marcos Rojo, who United are prepared to sell.
“So, we’ve got these last few days of the window and Manchester United are scrabbling around trying to satisfy their manager to a certain extent, and what they are doing is going to impact on the other Premier League clubs who are chasing a centre-back.”
Barcelona centre-back Mina, 23, is two years younger than Leicester’s Maguire and Castles believes the Colombian would be Mourinho’s preference.
“From what I understand if you were to give Jose Mourinho an option, between those two his preference would be for Yerry Mina,” he added.
“I think because he has those reservations about Maguire in terms of lack of Champions League experience, lack of top club experience, and Maguire being two years older than Mina.
“Yerry Mina has the potential to develop in his view.
“We’ll see what happens, but it’s going to impact other clubs in the sense that Leicester have to wait and see what happens with Maguire – they want to avoid selling what they see as one of their marquee players now after his World Cup.”