Well, you're pretty screwed at the RB position if you can't get McCoy so I could make that deal first although I'm sure you could trade Marshall in a pinch for a top tier RB if need be. So, assuming you can solve your lack of RB depth, I'd pull the trigger and try to get Rodgers.
12 team auction (100$)
Wilson 3$, Dalton 4$
Foster $30, Charles $16, Tate 2$, Wilson 10$
V. Jackson 10$, Boldin 3$, Garcon 4$, Witten, 4$, T. Austin $5, Patterson 2$, Tate 3$, Dobson 1$
Tucker, K 1$,Tynes, K 1$
NYG D, 1$