Thanks for all your inputs!
I understand your points about the story behind getting autographs in person and all, I am well aware of that.
I do enjoy the few signatures I have received in person, but in this case I was only looking for some background decoration. I thought a signed poster would look cooler than just a plain poster - and for around $ 75, I guess it would have been ok.
But anyways, I have now decided not to go for it.
After bidding low amounts on some of these posters and not winning them, I still got 2nd chance offers
for each single one, even if I was only the 13th highest bidder, so although the sellers claim they have only one poster, they probably have a whole shelf full of them that they offer anybody that was bidding.
Also, none of them could provide any of their "detailled information about the poster" etc. they would not have been able to provide anything but a "certificate of authenticity", abviously issued by themselfes.
On top of that, for some reason, almost all of the poster seller smake bidding private, to "protect your privacy"...
I may start working on a signed poster myself, but I know it will be a difficult task at this point in time. Maybe in a few years...