Anthony Martial, Kevin De Bruyne Top 'Overpriced' Summer Transfers, Study Shows

New Manchester United striker Anthony Martial is joined by Manchester City's latest purchase Kevin De Bruyne as the two most overpriced players in the summer transfer window, according to a recent study.

The CIES Football Observatory (h/t Richard Jolly of ESPN FC) suggest United paid €27.9 million (£20.4 million) over the odds for Martial, while De Bruyne's estimated value was €26.6 million (£19.4 million) lower than the €74 million (£54 million) fee City paid Wolfsburg for the Belgian.

However, while City overspent on De Bruyne, they also reportedly signed the most undervalued player of the window, with Raheem Sterling moving to the Etihad for €32.1 million (£13.4 million) less than his estimated €95.1 million (£69.5 million) valuation, per CIES.

Here are the top-five most overpriced and the top-five most undervalued players of the summer transfer window in 2015:

Overpriced
Undervalued
#	Player	Move	Estimated Value (million €)	Reported Transfer Fee (million €)	Difference (million €)
1	Anthony Martial	Monaco to Manchester United	22.1	50.0	+27.9
2	Kevin De Bruyne	Wolfsburg to Manchester City	47.4	74.0	+26.6
3	Christian Benteke	Aston Villa to Liverpool	26.3	46.0	+19.7
4	Angel di Maria	Manchester United to PSG	47.7	63.0	+15.3
5	Arda Turan	Atletico Madrid to Barcelona	18.8	34.0	+15.2
1	Raheem Sterling	Liverpool to Manchester City	95.1	63.0	-32.1
2	Mapou Yanga-Mbiwa	Roma to Lyon	19.9	8.0	-11.9
3	Robin van Persie	Manchester United to Fenerbahce	16.9	5.5	-11.4
4	Denis Suarez	Barcelona to Villarreal	13.7	4.0	-9.7
5	Nathaniel Clyne	Southampton to Liverpool	24.5	14.8	-9.7

It is largely unsurprising that the 19-year-old Martial tops the list as there was widespread incredulity when United splashed out such a huge amount of cash for the youngster on deadline day.

Though he is clearly very talented, his achievements to date do not warrant a £36 million transfer fee, and United are undoubtedly taking a big gamble on his potential, per the Mirror's Darren Lewis on Sky Sports' Sunday Supplement:

"

I don't think it is a risk as such but they have massively overpaid, whatever they say, for a player who has so far scored 13 goals for Monaco. He did not score any for Lyon before. They rave about him, they call him the new Thierry Henry. They can't speak highly enough of him in France. It's just an incredible amount of money to pay for a player who has done so little in his career.

"

De Bruyne has done more to warrant his £55 million fee, netting 10 goals and providing 20 assists in a stellar Bundesliga season with Wolfsburg in 2014-15, per WhoScored.com.

Another City purchase also takes sixth place in the overpriced list with the value of Nicolas Otamendi's switch from Valencia deemed to be €13.7 million (£10 million) more than expected.

Sterling's position as the most undervalued player of the window comes as something of a surprise as there was widespread speculation at the time of his switch from Liverpool as to whether he was worth £49 million, per BBC Sport:

He has started well with the Sky Blues and could prove a long-term asset for the Manchester outfit considering he is likely only to improve as he gains more and more experience.

Similarly Martial could yet prove his worth if he hits the ground running at United, but the Red Devils do indeed seem to have taken a big risk in splashing out on an unproven teenager.