The longer this goes on, the more I think what most of the 'ITK's' are saying sounds completely true (not that I didn't believe them in the first place).
Effectively what we already know is probably true- RM and Malaga have agreed fees. Isco probably prefers us (Pellegrini factor/playing time). We haven't offered as much as RM yet, and perhaps have a deadline to do so.
Unlikely that the selling of Tevez would affect our offer for Isco (as I am sure we knew we would be selling Tevez anyway) but you never know.
Ultimately I have no idea how transfers work, but I guess the above sounds reasonable.
That being said, I still think he is going to RM as all the noises indicate that. You can take Perez comment 'he wants to come to madrid' with a mountain of salt though, as he is hardly going to say the opposite.
I am sure we will find out soon enough, though.