I don't like to stick my head above the parapet because of the flapper tag but here goes ... the longer it goes on, the more I believe he's instructed his agent to manufacture a bidding war to drive up the Arsenal contract offer. At 28 going on 29 this is potentially his last big contract in Europe.
Arsenal are theoretically in the best position to offer him a whopping contract because they don't have to lay out a big fee to get him. In a year that advantage will be gone but in that year Sanchez could also suffer a career ending injury, so Arsenal have the leverage of offering certainty a year ahead of anyone else, if they say they'll decline to accept any transfer bid.
If Sanchez's priority was to play for City under Pep he'd have put in a transfer request. He's not done, possibly because that would mean he'd sacrifice some sort of loyalty bonus. Regardless, this is a clear demonstration that money is at least as significant a factor in his decision as footballing ambition.