Yup, vintage posters are a whole industry; they sell at Christies & Sothebys; so far I have spent $350 and $150 on my high ones.
Originals are impossible to get; esp, 70" full size; copies are smaller, fuzzy, blurry and colors are faded.
There is even restoration. I am having a Sebring '69 that I got free that was ripped, holes, falling apart, wrinkled (the seller refunded & gave it to me for free).
I am having it mounted on archival linen for $60 & have been told it will be like new.
Here is the classic Belle de Jour