If you are interested in expanding your DVD collection, there are a few that are on sale for under $5. Amazon often changes their prices, so be sure to check out the prices before purchasing.
Airplane! for $4.99 on DVD
Horton Hears a Who (Single-Disc Edition) for $4.99
Cloudy with a Chance of Meatballs (Single-Disc Edition)
Happy Feet (Full Screen Edition) for $4.99