They aren't "demands." He will be a free agent. The Suns had plenty of opportunity to offer him an extension or at least hammer out the framework of a new deal, and they declined. Maybe they still want him, but Nash has no way of knowing that. And, more to the point, he has no way of knowing whether anyone else wants him either.
I agree that some of the "roster upgrade" suggestions that Nash has been dropping here and there aren't demands. But I disagree that it will ultimately come down to whatever team pays Nash more.
Nash seems to be approaching this free agency as a way to be leverage his vision for the Suns in the next few years. One of the main reasons he never asked for a trade before this was that he made a commitment to the Suns by signing the contract, so he was only focused on fulfilling his end of the obligation to its fullest. In doing so, he was nodding to the fact that he was accepting that part of the NBA is truly a business. Now that he's no longer contractually obligated to give anything to this team, he is going to see what kind of pull he can have at the negotiating table. Because even though Nash realizes this is a business, he also has a fondness for the Suns - he would love to be able to go out seeing this Phoenix Suns' era, which he undoubtedly was the face of, go out his way. So, if him somehow structuring a deal with the Suns where he gets some of his demands - i.e. 3 years, guaranteed - but accepts an overall lower guaranteed amount of money so the the Suns can go after max level free agents this summer or next summer.
Oh, and you better believe Grant Hill's coming along for the ride as far as his legs can take him.
