The summer window has already witnessed several interesting additions to the Premier League.

Alexis Sanchez possesses the ability to become an attacking talisman for Arsenal, Manchester City have spent big on highly-rated centre-back prodigy Eliaquim Mangala from FC Porto, the goals of World Cup star Enner Valencia could bring West Ham to a new level and Liverpool have spent no less than £100million on seven first team signings - including the all-but-confirmed acquisition of Sevilla's Alberto Moreno.

But following an impressive brace against Real Sociedad in Chelsea's ultimate pre-season friendly, Jose Mourinho believes he has one of the bargains of the summer in £32million striker Diego Costa.

Rather pleased with himself, the Portuguese declared to reporters; "We consider the price very much in our favour. This is the player we wanted."

So is it time we considered the Spain international as one of the summer window's best value-for-money buys, or is the Special One, as per usual, simply blowing his own trumpet?

Well, in terms of pricing, it's hard to deny that the Blues have done good business.

After all, Costa's eight goals in nine Champions League appearances last season were only bettered by Zlatan Ibrahimovic and Cristiano Ronaldo - hardly competition you'd feel aggrieved about falling slightly short of. And likewise, his 27-goal haul in La Liga, firing Atletico Madrid to their first Spanish title since 1996, was trumped by Ronaldo and Lionel Messi alone. Once again, you can hardly criticise the Chelsea striker for missing out to two of the most proficient forwards in modern footballing history.

£32million is still a rather sizable fee for a player who has never set foot in the Premier League before and thus far only enjoyed one season of pure lethality, having previously amassed a rather uninspiring total of 77 goals in 226 career appearances.

WANT MORE? >> Chelsea transfer news | Latest transfer news

But compare it to some of the other transfer fees for top quality strikers in recent years. Radamel Falcao had scored just one Champions League goal for Atletico Madrid and only bettered Costa's league return by one during his final season at Vincente Calderon before Monaco forked out whopping €60million for the Colombian. That same summer, Edinson Cavani, also a relative novice at Champions League level, was acquired by PSG for a near identical fee from Napoli after netting 29 times in his final Serie A campaign. Yet few would dispute that in terms of quality, the Italian top flight is some way short of its English and Spanish counterparts.

There are more recent examples too, Luis Suarez's £75million move to Barcelona for instance. The Nou Camp side could have purchased two Diego Costas and thrown an extra million into the Christmas party budget for that amount. And the latest example of all; Chelsea recently sold Romelu Lukaku, a 21 year-old who just endured a near-humiliating World Cup campaign and offers no experience at European level whatsoever, to Everton for £28million. That's only £4million less than the Spain international, and despite the Belgian's immense potential, there are still no guarantees that he'll emerge as the world-class centre-forward he's widely heralded to become. Costa, on the other hand, is already on the verge of reaching that level - if he's not there already.

But it's not merely the fact that Chelsea have signed a front-man for, in comparison to recent transfers, an exceptionally modest fee. After all, the Blues could have allegedly re-signed Salomon Kalou for as little as £3million this summer, but that would have done little to improve their title chances for next season.

One could also point to Loic Remy -  the QPR striker who has bagged 20 goals in 40 Premier League appearances and is available to Champions League clubs for just £8.5million this summer through a release clause.

Rather, Costa symbolises one of the final jigsaw pieces falling into place at Stamford Bridge. He not only comes with proven goal-scoring credentials, but furthermore suits the Jose Mourinho philosophy perfectly. Perhaps it's too soon to start comparing the 25 year-old to Didier Drogba, although both Chelsea forwards share that ruggedness, aggression and confrontational mentality, yet the fact that Costa excelled under Diego Simeone, a manager whose philosophical views certainly echo Mourinho's, should not be overlooked as an indicator of how the striker will fare at his new club.

WANT MORE? >> Chelsea transfer news | Latest transfer news

Subsequently, the Chelsea manager has already remarked at how well the Brazilian-born front-man is transitioning to life in West London. "Diego is a team player. It’s not just about his goals but his defensive mentality and his ambition. He looks very much adapted to the team. He looks well adapted to his team-mates and our style," the Special One has recently informed.

Perhaps most relishing of all is Costa's age. He's younger than Sergio Aguero, Falcao, Cavani, Robert Lewandowski, Wayne Rooney, Robin van Persie, Luis Suarez, Jackson Martinez, Mario Mandzukic, Karim Benzema, Zlatan Ibrahimovic, Cristiano Ronaldo and Lionel Messi. My point being that, amid the clan of strikers currently considered to be amongst the best in the world, the former Atletico star offers the most longevity, despite his price-tag being significantly cheaper than the majority of the aforementioned names.

There is not one exclusive reason Costa represents fantastic business at £32million but rather a culmination of factors. Much like Alvaro Negredo, who tore up opposition defences after joining Manchester City last summer, the 6 foot 2 striker's direct, aggressive and bullish style if perfect for the Premier League.

It's even better suited to Chelsea in particular, who have spent the last two years searching to no avail for a genuine successor to Didier Drogba. And even if the Spain star can't immediately transition his potent La Liga form to the English game, coming somewhere close to the 19 Premier League goals Fernando Torres, Demba Ba and Samuel Eto'o found between them last season, whilst looking positive in open play, will be a cost-effective contribution.

And, as previously discussed, in the modern climate, a 25 year-old striker who has already proved himself at Champions League level represents sensational value-for-money at £32million.

Perhaps it is too soon to insist in such an assured tone - after all, the Premier League season hasn't even started yet and there's still two weeks until the transfer window officially closes - but even so, the signs suggest that Diego Costa will soon prove to be a sensational bargain for the Blues.

[ad_pod id='unruly' align='center']