Celtics ownership decided throughout the Kevin Garnett era that luxury-tax penalties were not a problem as long as the team contended. But for the first time in six years, the Celtics are facing a season out of contention for anything but the right ping-pong ball count. A team payroll of more than $70 million isn’t going to make a lot of sense for the first time since the 2006-07 season. With a harsh “repeater” tax scale — penalizing teams that exceed the threshold for the three previous seasons — set for activation in the 2014-15 season, the Celtics want to clear their books. What you see on the Celtics roster is probably close to what you will see in November. “In order for us to do anything in free agency, it would have to be through sign-and-trades, and free agency isn’t really our objective,” president of basketball operations Danny Ainge said yesterday after a press conference to introduce rookies Kelly Olynyk and Colton Iverson. “Right now, it’s not a priority for us. . . . We have too many players. We have logjams at power forward, center, shooting guard. But our job is to try and clean that up during the summer.” The first cut came Sunday, when the C’s waived Terrence Williams before $200,000 of his contract would have become guaranteed. Either via trade or the waiver wire, Ainge will continue to trim the roster. He indicated yesterday Rajon Rondo and probably Jeff Green are off limits, and teams have called seeking the price of each. But the Celtics don’t want to take on contracts until the 2014 free agent market. “Yeah, more likely than this summer’s (free agent market), yes,” said Ainge, who joked about not reserving a place in line in that Los Angeles hotel where Dwight Howard is now taking offers.