Three points-
1) You want to trade Spikes- Even if salary cap concerns were not an issue. This team has very few top rated players- Spikes is the very best. Trade him and you water down the talent even more.
2) The thought of trading him for Baltimore- After Ozzie Newsome stops laughing it will never happen. A)Ogden is a top 15 player in the league, Spikes is around 50 at best. B) Ravens have Suggs and Lewis. They do not need another linebacker.
3) You rarely trade an established player for a draft pick. How have the Bills 1st round picks since 1997 faired? Lets review. A. Smith, pick traded for R. Johnson, A Winfield, E. Flowers, Clements, Williams, trade for Bledsoe and McGahee, Lee Evans and JP Losman. Are any of those guys better than Takeo?