Manchester City manager Pep Guardiola believes Liverpool have spent well in paying £75million ($100million) for Virgil van Dijk, because he thinks high-qualy players work out cheaper in the long run.

Guardiola was interested in signing Van Dijk from Southampton, but missed out after Liverpool agreed a deal on Wednesday, with the player making the move officially when the transfer window opens on January 1.

City's manager has spent heavily on defenders himself since his arrival at the Etihad Stadium in July 2016.

Before the start of this season, he brought in Benjamin Mendy from Monaco in a deal that could be worth £52million, Kyle Walker from Tottenham for an initial £45million, and Danilo from Real Madrid for £26.5million.

That came a year after he spent £47.5million on signing England centre-back John Stones away from Everton.

"Liverpool took an amazing player," said Guardiola.

"Van Dijk is an exceptional central defender, that's a price we'll see (again) in the future.

"Sometimes the cheaper players are more expensive than the expensive players. If he played six or seven years at a high level it would be cheap. If he played not well, more expensive.

"John Stones, when he came here, people said he was too expensive. Now he's too cheap. It always depends on the value of what happens on the pitch."

- 'Nico has been amazing' -

Victory at Crystal Palace on Sunday would be City’s 19th league win on the trot, equalling Guardiola's personal record, set with Bayern Munich four seasons ago.

But the City boss has warned his players they will lose a league game sooner or later, and they have to be ready to bounce back.

"I have told the players many times that we are going to lose a game. It's important how we react," said the 46-year-old Spaniard.

"The problem is not losing a game, it's how you react and immediately win again. That's the most important thing in any league if you want to win the title.

"It will be news, OK, finally Man City lose one game. That will not be big news. The big news will be to win again immediately.

"I insist many times, this isn't real or normal, we are going to drop points and that's when I want to see my team."

Guardiola suggested much of City's recent form is down to Argentinian centre-back Nicolas Otamendi, who has been their key defender during the injury absences of Kompany and Stones.

"We have a super man in the team, as Nico Otamendi helped us absolutely," Guardiola said.

"Without Nico, it would not be possible, what we have done.

"Everyone speaks about a bit of players such as Raheem (Sterling), like David (Silva), like Kevin (de Bruyne), like Sergio (Aguero), and they deserve it, but if I would like to point to a player who deserves full respect, for what they have done until now, it's Nico.

"Nico has been amazing. He is a guy who even with pain in the ankle, in the knee, in the back, he always fights. He's one of the hugest competitors I’ve ever seen in my life.