Surely it depends on how long he has left on his contract and how much he would try to push through a move if we did show interest? As if he is within a couple of years of his contract running up and we made it clear we were interested and he made it clear he wanted to come to us, we would get a better price. If we got a striker in January i'd be happy with a move for Fellaini in the summer.
Agreed besides we tend to overate players like Fellaini. He's a good player but besides 'hair volume' Diaby can match him in just about every area. Holtby will be a different class though.