Pats traded for Moss, Branch, and Welker. I don't really consider 35 year old Fred Taylor a big signing nor Sammy Morris. I guess maybe Adalius Thomas in 2007?
The Bills didn't say they wouldn't sign anyone, just that they wouldn't be active in the first few days spending big money. Almost replicating exactly what the Patriots have been doing the past few years. Other good teams do it also.
Rosters from San Diego, Pittsburgh & Green Bay are all almost entirely made up of draft picks. Not coincidentally Nix and Whaley came here from two of those teams.