The problem is that there just isn't a lot of value out there at the moment and Fergie can see that. As good a player as Modric is, we wouldn't be crazy to spend £40m on him when he's worth £25m at a very big push. People who are desperate for us to sign him are just desperate for anyone to come in.
I'm a big fan of Martinez and would advocate us getting him. Whether Fergie feels there is value in buying him or not I'm not sure though. I'm hoping he takes a risk and does splash the cash on him.
We're in this situation in football though at the moment where there are four world class central/defensive mids all at one club in Barcelona, which vastly reduces the world class midfielders we are able to sign.
Alonso and Schweinsteiger would both be perfect as well in my opinion, however we're not going to be able to get either of them either unfortunately.