I don't think any of the top FAs will sign with Boston until Ainge goes out and acquires another star to put alongside Rondo first.
Chicago and Houston are ready to challenge for NBA Championship right away. Boston are not and are thus not competitive from a basketball point of view with the best offers on the market. Ainge needs to get another star in here to make them competitive.
So I would say there is no point in creating cap space unless you are targeting one of the second tier stars like Greg Monroe, Eric Bledsoe, Gordon Hayward, Chandler Parsons or Pau Gasol ... because the A listers are not coming.
Well the point is not to create cap space for the sake of cap space, just to illustrate you CAN achieve it (with a bit if help of course) if there's mutual interest between player and team. In reality, it's no different than what Houston needs to do in order to open enough space for Melo.
Chicago... well, that's an intriguing beast. They DON'T have enough for MAX cap space. They amnesty Boozer, and they only have about 14 million to offer Carmelo (and that's without including their rookies). Their alternative is to trade Taj Gibson to create the space, and he's on a 3-year deal... so you'll have to see how that would play out.
So it's not all so simple as Melo deciding to go to Chicago. Can they manage it? Sure, but they have some obstacles, and would need to trade and amnesty guys who have been part of their core in the last couple of years to accomplish it.
Heck Melo is considering the Lakers (I don't know how serious he is), but they're in an even worse position than all the teams he's considering.
I don't see it all being sunshine and flowers at the other destinations.`
As for Houston they need to trade Asik (and their trade partner needs to clear space in order to do it because as it stands it's an illegal trade) and also trade Lin (who are potential takers?) and also renounce Parsons (and there won't be enough money for him, unless he agrees to a very crappy deal).
So all these teams have obstacles that might prevent them from getting Melo, even if both sides have interest.
Anyways, that's my stance on the Melo situation. Not that we would be his ideal destination, but we're not as far from the pack as people want to insinuate if we were to throw our hats into the ring.