Yeah, the autographs on this CD are authentic. However, Ozzy's signature is upside down (and quite small), Tony's signature is faint/smeared and Geezer's signature has an additional "G" in the background. Overall a pretty horrible looking piece, even if the price does somewhat reflect that.
I think it will be worth the extra investment to go for one of the first six albums with nice clear signatures. While all the members are still around, collecting a full set has become pretty impossible. Even during the 1999-2005 reunion tours, it was never easy getting them all.