Not So Luxurious
The NBA salary cap was recently announced and the luxury tax only moved up to 67.8 million which doesn't do the Celtics any favors. After signing Brandon Wallace, the Celtics' payroll is now at 64.4 million. If we don't pick up Allan Ray's option then the Celtics will be around 63.8.
In terms of future moves, the Celtics could sign someone for about two or three million. I doubt that the owners will let Ainge go right to the tax limit because if they do, and something goes wrong during the season, the team won't be able to sign anyone to a 10 day contract or else it will put the Celtics over the tax and cost them the revenue sharing that sub-lux tax teams get a piece of.
So basically, the only hope this team has to make even minor changes is via trade. The problem there, of course, is that the Celtics' assets aren't that valuable right now. In order to get a good point guard, the Celtics will likely have to deal Rajon Rondo. Perhaps the C's could acquire a capable backup for less than that but we'd be lucky if an Anthony Johnson-level player came that cheaply. With so many teams looking for backup point guards, it is unlikely to be a buyers market. Gerald Green wouldn't almost certainly have to be dealt to bring in a big man of middling quality.
Theo Ratliff's contract loses some value because, whlie other teams might be more anxious to dump a bad contract, the Celtics can't exactly afford to add salary in fear of being over the tax for next season. Odds are, Ratliff will likely be held onto and Ainge will look to investigate trades at the deadline when more teams might be looking to rebuild and dump a quality player just to get rid of the contract.
In the end, Danny Aingeg is going to have to trade better than he ever has before in order to upgrade the current roster. And since most teams understand the predicament the Celtics are in, it's unlikely that we'll have any leverage in any trade talks.