In your case it's indeed a good thing you did a quickopinion! But I already bought my item, maybe if seller would refund the quickopinion...:-)
I'll wait a bit, maybe I'll first get some valued opinions here from nirvana experts.
I opened a seperate topic in the music section for this item.
I asked Roger's opinion but he answered he doesn't do Nirvana autographs.
Then I did a quickopinion from PSA and got the answer likely genuine.
So that's ok for me. Considering the positive reactions on this seller and no reaction in the other thread, I'm gonna keep this item:-).