Scott Cunningham/Getty ImagesJulius Peppers' $12.383 million cap number proves the Bears are not afraid to invest in defense.

When is enough, enough? That seems to be a fair question to ask of the Bears in the hours leading up to free agency. As it stands right now, four of the team's six highest cap numbers belong to defensive players: Julius Peppers, $12.383 million; Brian Urlacher, $9.7 million; Charles Tillman, $7.966 million; Lance Briggs, $5.996 million; with the other two reserved for Jay Cutler, $9.6 million and the recently franchise-tagged Matt Forte, $7.7 million.

Since 2004 under head coach Lovie Smith, the Bears have drafted at least one defensive lineman every year, except t in 2005 when the club pulled off a trade for with Miami for defensive end Adewale Ogunleye that cost the organization proven wideout Marty Booker and a third-round pick.

2004: Tommie Harris, DT, 1st round; Tank Johnson, DT, 2nd round, Claude Harriott, DE, 5th round
2006: Dusty Dvoracek, DT, 3rd round; Mark Anderson, DE, 5th round
2007: Dan Bazuin, DE, 2nd round
2008: Marcus Harrison, DT, 3rd round; Ervin Baldwin, DE, 7th round
2009: Jarron Gilbert, DT, 3rd round; Henry Melton, DT, 4th round
2010: Corey Wootton, DE, 4th round
2011: Stephen Paea, DT, 2nd round

In 2009, the Bears sent a second-round draft choice to Tampa Bay for the late Gaines Adams.

Add it all up: the Bears have spent the equivalent of nine draft picks in the first three rounds on the defensive line, plus they signed Peppers to a monster deal in the months prior to the 2010 season.

Compare that to wide receiver, where the Bears have used exactly four picks in the first three rounds since 2004 -- Bernard Berrian (2004), Mark Bradley (2005), Earl Bennett (2008) and Juaquin Iglesias (2009) -- and made one notable free agent signing in the form of Muhsin Muhammad back in the spring of 2005.

Doesn't this beg the question: When is enough, enough?

Mario Williams is a fabulous player, who at 27 years old is entering the prime of his career and would no doubt benefit from moving back to a 4-3 defense. But how much more can the Bears possibly give the head coach on defense? Don't get me wrong; the Bears need to upgrade their pass rush. But should they dole out another huge deal which could perhaps cost them $40-$50 million in guarantees to do so?

People point to the dominant defensive line of the Super Bowl champion New York Giants to justify why the Bears would be wise to add Williams in free agency, rather than Vincent Jackson. But last time I checked, the Giants also had these guys named Hakeem Nicks and Victor Cruz on the roster.

Sometimes it feels the Bears need to be reminded of that.