One thing I would say is if you want an autograph you might want to get it now.
I say this because after waking from my stroke and three brain surgeries last year, I awoke to find a few of my favorite authors were dead. The books I now have signed those are it.
(My favorite book, the golden a vampire book by Lucius Shepard I have signed, he died recently)
Kind of tragic to have lived but seen others die. Maybe just get the signature now, if it's important to you.