Slickerbill,Biograph is worth picking up. It has some very good stuff on it. However, I'd recommend getting Blood On The Tracks, Blonde on Blonde The Bootleg Series 1-3 and Highway 61 Revisited before getting Biograph. Don't be concerned about seeing him live, there was a time that he wasn't very good, but his heart is back in it, his band is wonderful, it will be a great show. Where are you seeing him?
Is he happy? I think he finally is. There was a time that an entire generation hung on his every word. I think the pressure is off and he's enjoying his new role as "Just a Guitar Player".