It also depends on the title. That's the most important thing about collecting posters and what you pay for them. There could be a 40 year old poster that you could get for $10 or an A title that would go for hundreds if not thoiusands. For example, Breakfast at Tiffany's is only about 45 years old but the one sheet usually sells in excess of $3,000 at auctions. And there doesn't seem to be a shortage of them. Who else wants the poster, is it a hot title, and what are others willing to pay for it. The next consideration is condition. Is it in decent shape or is it in poor shape? A lot of factors to take into consideration.