This is a high risk, high reward ordeal. You're picking up the someone that's going to be the starting RB for the season on a prolific offence.
Regardless of talent level, he's likely to put up flex position worthy points consistantly. And coach has already said he considers him an every down back... and this was before the injury.
This is a golden egg move if you can get him at the right price. I'd plan to shell out $60-$70 on him.
Otherwise you can hold out for one of the few other players that tend to surface throughout a season and pray you don't get outbid.
Personally I'd go for it but I wouldn't do more than $70 at the absolute max.
could really use some help with this one... http://www.fantasyfootballcafe.com/forums/viewtopic.php?t=473643