So, I’ll get us started to set the tone…
CAVEAT EMPTOR
About 14 years ago or so, I was eyeballing a Star Trek- The Motion Picture theatrical poster (27x40) signed by the entire cast, and Roddenberry. The seller claimed to have a collection of them acquired at some event, and would post them for auction regularly. I almost always got out-bid at the last second. They would generally go for around $200.
Anyway, after several weeks of relentlessly hunting this sucker down, I finally won one for about that amount. In anticipation of its arrival, I went out and bought a nice frame, and was really looking forward to displaying it in my apartment (pre-wife days hahaha).
The poster arrived and I gladly opened it up, carefully examining its beauty. It was exactly as described, and the signatures all looked legit and written in nice marker. Unfortunately, then my inspection turned up the horrifying reveal: In the bottom right corner of the poster was the text "www.zipzapposters.com"
Needless to say, this tipped me off to what I should have otherwise guessed if I hadn’t been drunk with desire on getting this item: IT’S A FAAAAAAAKE!
I mean, Roddenberry passed away in 1991, which was LONG before the existence of anything even remotely resembling “zipzapposters” would have been in existence. There's no way he could have signed this poster.
So, lesson learned- I never EVER buy “autographed merchandise” off eBay now. Ever.
I've been collecting in person autographs for four years now. I have no intention of selling but in case anything ever happened to me I had the had the first 25 autographs authenticated so that the inheritors could sell it much easier. The internet, and even most of the stores, are full of fakes/autopens. Authentication isn't 100%, fakes still get through, but it does add some piece of mind.