I hate to admit it...But i actually think I would rather have Scal than Foster.
I too hate to admit the feeling that Scal actually has a role this year. He's irreplaceable for his abilities and what we have for trade value. I would only keep Pat0, BBD, Giddens, and Tony on the trading block. Powe for the right player, as well as Pruitt and Walker.
Scal is not irreplacable by any stretch of the imagination. He is a hustle guy who doesn't shoot very well or defend very well and is not very athletic. Those are not very good combination of attributes.
I think to get Foster you need to trade Scal, for the salary portion, and then kick in a prospect, maybe Giddens and a 2nd rounder. I'd do that trade as it shores up the Celtics big man need right away. Then you look for say a Marbury to play a backup PG role.
The thing is that the trade deadline is coming up fast - Feb 19th. So the C's, if they want to make a move better start talking to some teams now!