asking here is one way to find the honest sellers.
Dale is top notch and I would also suggest Jason Edgerly, also a member here
on my site, my auctions show the exact item being sold this week and I began using a measuring tape installed to my photography background so you can see the size next to the poster, although admittedly, we don't always line up the posters perfectly and may be 1/16 or 1/8 inch off
set sale items may be a stock photo, but have no doubt that any poster in stock will match perfectly the image of the item listed and in that same condition
ebay sellers - there is considerable variation between dealers, many of whom are not pros (meaning, it's not their day job), but asking here gets the answers
good luck on your collecting!