Gonna defend Klopp & Liverpool a bit here - yes it's an overpay (I'd value him at about £50-55m), but they absolutely had to get a top quality CB in ASAP to replace Lovren in the XI, and Van Dijk is probably the CB around who fits them best.
Issues I've noticed with Liverpool's defence this season:
- Struggled to defend through-balls due to lack of recovery speed.
- Been easy for runners to time their movement off the shoulder of defenders - due to inability to align defensive line properly and defenders being staggered and out of position.
- Poor defending set-pieces and aerial duels in their box.
Van Dijk is probably the most dominant CB in the air in the PL, and quick. He's also been spoken about as a leader, and thus should have the ability to properly organize Liverpool's defence (Liverpool also lack regular XI leaders in general, so he could be a future captain).
He's also technically good and comfortable and composed on the ball with the ability to play quick balls over the top.
So all-in-all, yes I think they've overpaid and their were potentially cheaper options on the board like De Vrij, Inigo Martinez, Koulibaly, Manolas for between £30-45m, but none of them combine the physicality, ability on the ball, leadership and PL experience that Van Dijk has.
I agree with what Klopp said really - sometimes you have to forget the fee and think about the player you've attained, i.e. sometimes you have to overpay for the player you really want, and it's not always a case of just you being one-tracked minded and you should look at other targets, occasionally a player is just by far the best option for the way you want the team to play.
It's a shame he looked like a hypocrite in the process of making this point though after his Pogba comments.