Cheaper alternatives to Marouane Fellaini for Arsenal

It seems Marouane Fellaini could be joining Arsenal in a deal that could cost the red half of north London around £50 million in total over his contracted years, but are there any cheaper alternatives?
It seems Fellaini is a bit of an anomaly thinking about it, he has the height of a centre back and the power to go with it, the footballing brain and discipline (sometimes) to play defensively in midfield and support the attack, but also has the ability to lead the line ad score goals, so I don’t think Arsenal could get someone like him in all aspects. But Arsenal only really need his defensive parts of him. They seem to have a certain centre back pairing in Laurent Koscielny and Per Mertesacker, but there’s always a worry they’re frail in front of that. Since Alex Song left, Arsenal fans have worried they’re missing the steel in midfield that every top club needs, even though in my eyes Alex Song wasn’t the Patrick Vieira type player they’re lacking, just a deep lying playmaker if you wish.
So if they’re after a defensive midfielder, here are three who could fill that void that aren’t exactly the most well known defensive-minded midfielders who Arsenal would never sign, for example; Michael Essien or Xabi Alonso. 
Number one, Sven Bender of Borussia Dortmund, who when he signed for Dortmund was largely regarded as back up for club captain, Sebastian Kehl, but Bender and Nuri Sahin were a huge factor in Dortmund winning the league for the first time in seven years in 2009. This guy is an absolute tactician who doesn’t need blistering place to be able to play and just reads the game instead, would be a great option for Arsenal, but largely unlikely due to Dortmund’s impressive European campaign last year and he signed a contract extension to keep him in the yellow of Dortmund until 2017. 
Now another alternative could be Sven Benders twin brother, Lars. Like his brother, Lars was seen as just an extra body in the Bayern Leverkusen midfield when Michael Ballack joined the Bundesliga team but instead had a breakthrough season and played consistently well in the 2010-2011 campaign. Much like his brother, he is an absolute student of the game and can read the play as it acts out and doesn’t mind a tackle or two. Previously linked with Arsenal, he is easily more viable than his brother in getting him to sign.
 
The last idea I had was Asier Illiarmendi, who was in the Spain U21 squad and winner of UEFA U21 Championship recently. I don’t know as much about him or know what he plays like for his club team Real Sociedad but from limited viewings of him this summer, he comes across as a kind of metronome like player, his passing was superb and if I’m not mistaken, had a ninety plus pass completion rate throughout the tournament (I’m willing to be proven wrong). Another player that has been linked before the Fellaini deal become more prominent.
So there’s my scouting report on players who would do the same job of Fellaini in a certain aspect, but for cheaper, I hope.