The Patriots use the back end of their roster (particularly the 53rd man) differently than most teams in the league. The Pats 53rd guy usually plays and is usually a specialist needed for a certain game (or games). In the past it's been an extra dlineman, this year it's been an extra tight end or wide receiver. Stephen Spach might be re-signed again this year (like TE Rivers was a revolving door last year), when the Patriots decide they need a 3rd TE. Eckel is on call for RB depth, and CJ Jones probably would be brought back if the Punt Return depth got short. This essentially gives the Patriots a deeper roster than most teams as they mix and match that last spot on the roster while most teams stay with a consistent 53 unless their is an injury. My guess is that Price was signed because Aiken is still working his way back and Washington is injured. Aiken got snaps at WR and on special teams against Miami and maybe the staff feels he's not ready for both roles at this point. Or it could be simple as the Patriots need an extra WR to run routes during the bye week while Moss (who's had the back injury), Welker (ribs earlier in preseason) and Gaffney (some injury I can't recall) take a few less. By this time next week, the Patriots could decide they need an additional safety or corner...who knows?