I don't think that much. I'm guessing mid to high teens. It's a converted '74 that was a 318 non-Rallye car I think. Nothing special to begin with.
The white Challenger from Death Proof went for about $11k. I forget how much the In Time Chalelngers went for, as this one was used in that movie as well.
But since it has Wahlberg's butt print, who knows how much more it'll be worth...