When it comes to buying movie memorabilia, I'm a fan of the small and special pieces, unless a large piece is too cool for words. (Also, smaller stuff tends to be cheaper, so you don't have to be a billionaire to grab something!)
These don't seem to be the actual, used movie props, but check out this collection of papers from Indiana Jones and the Last Crusade. If you're a fan of the series and like to collect funky stuff to display, this would be a sweet and super-cheap addition. As of noon today, the current price hadn't hit $20 yet! The set includes Indy's ID, fliers, a zeppelin ticket, a Nazi telegram, and even old photos of Indy and father Henry. It's the sort of cheap add-on that can make an Indy Halloween costume all the cooler, or make your movie geek display even more complete.
Stay tuned for more -- actual props and crazy replicas could be yours ... for the right price!
Or check out this more expensive and thorough paper collection -- in a replica book.