Borrowing from indispensable salary site ShamSports.com, here's a salary matrix showing what the Boston Celtics have for contracts over the next four seasons (no player is under contract beyond that):
Red = Player Option | Blue = Qualifying Offer | Green = Team Option | Orange = Nonguaranteed
Keep in mind a few things when assessing how Boston will proceed. The salary cap has been $58 million in each of the past two seasons. The luxury tax line was $70.3 million for the 2012-13 season. By using the full value of the midlevel exception to sign Jason Terry, the Celtics were hard capped, meaning they couldn't exceed the luxury tax apron of $74.3 million.
With 14 players signed for next season -- albeit four with nonguaranteed deals -- the Celtics project to be over the apron (depending on where the luxury tax line lands). That would seemingly make it likely that the team would be limited to the less valuable taxpayer midlevel, which allows for a maximum starting value of $3.183 million (it can also be split among players). If the Celtics can stay on or below the apron, they could use the non-taxpayer's midlevel, which starts at $5.15 million (remember Boston must remain below the apron even after using the exception).
Boston also has the biannual exception available this offseason, but only if it does not use the taxpayer midlevel. There's incentive to avoid going over the apron this season as incremental tax rates loom that will drive up how much teams pay in luxury tax (more than the dollar-for-dollar tax that existed in the past).
Moving forward, we'll examine the options that exist for the Celtics this summer, but let this matrix serve as reference for those discussions.