Top-tier players like CP3 are looking to join other top-tier players in what seems to be a league where only 4-6 teams are relevant and the other squads are just fodder. It started with Boston when Garnett and Allen joined Boston. Then LeBron and Bosh go to Miami. Melo gets traded to Stoudemire. So on and so forth.
You dont hear about CP3 or Howard going to teams like Utah or New Orleans, but rather the Lakers and the Knicks. Parity in the NBA is already non-existent. In a few years, IMO, it will be so bad that it will feel like there are only 4 teams in the league, to the point where the talks about contracting teams may become real. And the benefactors are teams in huge markets.
With that said, CP3 isnt going to be a Sun. Not in this lifetime.