Gotta look at past trades to establish value, and exclude any fluke trades(basically anything the Raiders have done).
Hes not as "blockbuster" as Kevin Kolb or Daunte Culpepper. Kolb was a relative unknown who had potential and Culpepper was a former high performing starter.
Hes not as bust as, say, Trent Green was for us, who we spent a conditional 5th on. Or even a Shaun Hill type situation who went for a 7th.
Steve McNair went for a 4th and id say that sounds about right. Though id have a hard time seeing anyone spend a 4th on a fourth year vet who hasnt lived up to expectations.