I get the reasons against this idea, but would the buying price really be that high?
He's a well known sick note at this point, and even if his wages are high now when does his contract end? He could sign for far less per week to get a 3 or 4 year contract extension and know he will get more game time. Is he worth taking such a risk? I can see the temptation. He's also HG (no?) so that helps us in that area as well if we decide to move one of our other HG players out if they are deemed a surplus after next season (Stones or Delph).
I think he's not our #1 option, but something to consider if other things don't go as we hope as even if he is out injured we have SJS (all who should improve) and Kun still around, but we don't have to play him every week, so that can keep him fresher.