sounds like you're in a 10 man and would have 5, 20, 21, 25. So you basically be moving from Chris Jonhnson to Frank Gore (Who should have the best year of his career) for a shot at an extra Shonn Greene/Ryan Mathews/Miles Austin. That sounds pretty good to me initially, but Is the difference between CJ and gore larger than who you might get early vs. regular pick. Let's look at the running backs. IS the diffrence between CJ and Gore less than Gore and Beanie/Knowshon? Last year it was 120-60 and I'd say no deal. This year I think it'll be close to even. At WR the difference is between Gore and Miles Austin was about 30 last year (keep in mind Austin didn't even get a start until week 5!) and will be even closer an higher. RB points are at more of a premium however.
Verdict. I think I'd go for it. Although on paper it's a virtual; break even for me, there's an extra, high round body in your lineup and you know for a fact that someone is going to slump, get injured or have a REALLY tough matchup while the extra guy is playing against the Palmdale Pop Warner Allstars. So I can easily see it winning you and extra game or 2.