Harry Maguire is officially a Manchester United player after completely a move in the region of £80 million.

We can all agree that the Red Devils have bought themselves one of the Premier League's finest defenders, but his world-record transfer fee was always going to raise eyebrows.

That's especially the case when you consider he's stepping into the shoes of Virgil van Dijk, who previously held the title after swapping Southampton for Liverpool to the tune of £75 million.

Not only that, but the incredibly highly-rated Matthijs de Ligt made his move from Ajax to Juventus for a £67.5 million fee that now looks an absolute bargain.

So, while it's the dream move for both United and Maguire himself, there will certainly be no shortage of pressure on him to sure up the leaky defence at Old Trafford.

Maguire's world-record fee

Maguire can at least find solace in the fact that transfer fees have been going through the ceiling in general this summer with clubs like Real Madrid and Barcelona splashing the cash.

It really makes you wonder what players are actually worth and just how much, through cunning negotiations and contract obligations, are selling clubs driving this bonkers trend?

Well, in amongst all the summer chaos, Transfermarkt stand unbiased as perhaps our greatest objective source of 'true' transfer values by keeping tabs on thousands of top players.

Most over-priced transfers

That, in turn, allows us to compare their data-based valuations to the actual transfer fees to see which moves have been the most 'over-priced.'

To give an example: Atletico Madrid signed Antoine Griezmann for £48.60 million in 2014, despite having a value of just £27 million, meaning that he was over-priced by £21.60 million.

Get the picture? So, without further ado, here are the most over-priced transfers in footballing history of which Maguire is now a part:

1. Neymar to PSG - £109.80m 

Transfer fee: £199.80m

Actual valuation: £90.00m 

2. Ousmane Dembele to Barcelona - £82.80m

Transfer fee:  £112.50m

Actual valuation: £29.70m

3. Kepa Arrizabalaga to Chelsea - £54.00m

Transfer fee: £72.00m

Actual valuation: £18.00m 

4. Joao Felix to Atletico Madrid - £50.40m

Transfer fee: £113.40m

Actual valuation: £63.00m 

5. Philippe Coutinho to Barcelona - £49.50m

Transfer fee: £130.50m

Actual valuation: £81.00m 

6. Virgil van Dijk to Liverpool - £49.19m

Transfer fee: £76.19m

Actual valuation: £27.00m

7. Aymeric Laporte to Manchester City - £36.00m

Transfer fee: £58.50m

Actual valuation: £22.50m

8. Neymar to Barcelona - £34.38m

Transfer fee: £79.38m

Actual valuation: £45.00m

9. Harry Maguire to Manchester United - £33.30m

Transfer fee: £78.30m

Actual valuation: £45.00m

10. Gareth Bale to Real Madrid - £32.40m

Transfer fee: £90.90m

Actual valuation: £58.50m 

11. Paul Pogba to Man Utd; 12. Romelu Lukaku to Man Utd; 13. Cristiano Ronaldo to Real Madrid; 14. Kevin De Bruyne to Man City; 15. Luis Suarez to Barcelona; 16. John Stones to Man City

It certainly isn't an exact science, but it definitely throws up some interesting results and it will come as little surprise that Neymar is number one with a whopping £109.80m differential.

Meanwhile, Barcelona are guilty of paying way over the market value for Dembele, Coutinho and Neymar, while United also make their fair share of appearances.

If these numbers tell us anything in particular, though, it's the club that are willing to throw the most money at a player when they really, really want them. 

What do you think is the most over-priced transfer in history? Have your say in the comments section below.