Honestly, I think it will be more than that. I think it takes a minimum of three first rounders plus other picks to get it done. Thats been the rumored price for most of the year.
It will be a first round pick this year, and then a first rounder next year. The Bengals, Pats and Browns own two first rounders apiece this year, so any team wanting to trade for the #1 overall pick will need to talk with them to get the third first rounder, so that is certainly going to cost a player.
Me personally, I don't think it will be worth it. As for my team, I don't think that the Redskins will do it- I think they are willing to sit back and wait for RGIII or Jones.