As an aspect of team building and team maintenance, signing veteran NFL free agents is becoming less attractive by the year.

The problem is mostly timing vs the life expectancy of an NFL career. Drafted at about age 22 and finishing the rookie contract at about age 26-27, most NFL guys have that one big payday at that time point. By the time the second contract ends they are old and declining.

The biggest problem regarding this is that after they bust their hump to perform through the rookie contract to get the big payday they are likely to taper off once they have hit that financial security milestone. Injuries have accumulated as well. Realistically, why would they be eager to further deteriorate their long term physical well being until the next contract where they will likely be a 30something guy on a steep decline no matter how much or little abuse they were willing to take?

Any team can only have so many guys they pay top dollar; very few really. The aforementioned factors only emphasize that the draft is crucial and impact players must be gained in that if you wish to be successful.
So free agency is a very treacherous practice in the NFL and it is no surprise that teams who heavily invest in that generally don't do very well. In general BB has shunned that aspect of team building for some years now and looks for the guys seeking a one year deal for cheap so they can prove they still have it or guys that are younger and cheap who are potentially good but have played in somebody's shadow or otherwise have been under the radar. So if you see some big name is available at some point don't expect BB to make the move. He's too smart at this stage to jump into that black hole.