I think Powe will get around $3.5M per year, probably for 3 years, and probably from Boston. A little more than Landry, but not as much as Turiaf, the main reason being (fair or not) the height issue.
It is actually in Boston's favor that Powe is a FA next summer. I suspect the market to be relatively light, not many teams extending big contracts. I think most teams are going to be careful with their spending -- many teams are hoping to lure one of LeBron/Wade/Bosh and as a result few teams will want to offer cap eating contracts to mid-level players.
I really think BBD is the odd man out going forward.