dump bin 
noun
A promotional box in a shop for displaying books or other items.Along with remaindered books, DVD dump bins are sources of unappreciated gems....
- Posters, cardboard cut-outs and dump bins make up the remaining £40,000, which seems rather a lot to us, so there were probably some other, miscellaneous games in there too.
- What, did you buy your grimoires or whatever from the dump bins at the book store?