My wife worked for a movie theater for several years. During that time, she amassed a few dozen movie posters and a few of the transparent marquees- the things that went in the small rectangular light bars advertising what movie was playing. Most of these are not from big name movies. Mainly they're from the 90s to early 00s. They have all been stored rolled, and many have thumbtack holes in the corners.
We'd like to sell off some of this stuff. Aside from eBay, where's a good place to find values?