If he actually is available for 10m-12m we really should go for him. He's not the superstar signing that we may crave but he'll be a wonderful option to have in the centre of the field. Henderson's the only midfielder that seems capable of scoring (bar Gerrard penalties and odd goals), yet I still have doubts about him being the goal scoring midfielder that a top 4 club needs, even as second choice. A classy, very young yet very experienced player would be very welcome in our squad.
I think it may simply be a case of Ajax wanting too much money for a player with only a year left on his contract. Seems quite loyal, and insists he won't leave the club on a free, which means he might sign a new contract should no offer come in, thus Ajax's stance.
Can't see any other reason why no clubs have gone in for him. Even the smaller clubs that could easily pay 10m or 12m for a player of his quality, if that was the price, haven't made an attempt at signing him. Has to be the price tag.