Gary Neville says the £75m fee paid by Liverpool for Virgil van Dijk is "incredible", but will prove a good deal if he helps his new club win trophies.
It was announced on Wednesday evening that a deal has been agreed between Liverpool and Southampton to make Van Dijk the most expensive defender in history.
And former Manchester United centre-back Neville told Sky Sports: "It's a lot of money! When I first heard it I thought 'wow, £75m'. I'm not surprised by the actual transfer but that is an incredible amount of money.
"Liverpool need defenders and have to pay to get him. That's the way the market is and it isn't going to change."
Van Dijk will complete the move on January 1, having been pursued by Liverpool in the summer and handing in a transfer request in an effort to leave St Mary's.
Liverpool ended their pursuit on that occasion as Southampton complained the Reds had made an illegal approach for the centre-back.
But, having been criticised at times this season for their defending, Liverpool have now got their man for a fee that eclipses Manchester City's £53m deal to sign full-back Kyle Walker in July.
"It sounds like a fantastic deal for Southampton," said Neville. "But if Liverpool can stop their creaking in big matches when put under pressure then it will be a good deal for Liverpool as well because people will forget about the money that has been spent in a year or two if they can win trophies and get the defence right.
"Liverpool have to get the defence right, in the bigger matches they do stress quite quickly and can crack, so from their point of view, paying that sort of money hopefully it pays off, but for Southampton they would snap your hand off for £75m.
LISTEN: Transfer Talk podcast
Click here to listen to the latest Transfer Talk podcast where the futures of Alexis Sanchez, Mesut Ozil, Virgil van Dijk, Antoine Griezmann and Philippe Coutinho were discussed
"Over the last few years they have lost some good players for good money but nothing at this level. It seems like a fantastic sell.
"I was surprised in the summer when I saw £50m for Kyle Walker but he has done brilliantly and it's just the way the market has shifted to an incredible level that shocked me."