Follow the link if you want the full breakdown, which Speier has broken up into multiple categories: fixed salaries, arbitration eligible (meaning the unsigned David Ortiz and Alfredo Aceves), estimates for pre-arbitration eligible players, notable minor league deals (i.e., Aaron Cook and Vicente Padilla's possible $1.5 million deals), and, of course, "other".
The gist? The luxury tax threshold is $178 million, and the Red Sox are currently estimated, before they sign anyone else, to be at about $170 million without counting the $14 million extra spent on the medical staff, the 40-man roster, and bonuses. If they are forced to go to arbitration with Aceves or Ortiz, that number could rise or fall, but there is room for a signing there (such as the rumored offers for Roy Oswalt and Edwin Jackson, assuming the two can't find the higher-priced work they want elsewhere), or just of flexibility for the regular season, should they wait until the price falls on someone like Gavin Floyd, or even Wandy Rodriguez.
This is also a good place to remind everyone that Boston's opening day payroll in 2011 was just under $164 million, and that they ended up paying the luxury tax for their 40-man roster by year's end. They aren't "cheaping out", even if they did deal Marco Scutaro partly for financial flexibility -- if anything, they're likely ahead of last year's pace, and just as likely to pay the tax once more with baseball's second-highest payroll.