If you are someone who looks to buy a lot of movies, you can contact a wholesaler for this purpose. You will probably need to order a good number in order to get a great rate or be a long term client with a minimum number of purchases each month. If you buy a lot, this is an ideal option.
There are some movie clubs that are run by studios producing these films. They offer great prices and one can make use of specials that are on offer every now and again. Once you join, you generally get a good deal on your first few DVDs as well. You can always get preferred rates ahead of non-members and can get the first chance to receive the latest releases on DVD as an added advantage.
Online Auction Sites
Online auctions sites such as eBay and amazon.com provide you with an option to buy cheap DVDs. These could be brand new as well as slightly used ones. The price will certainly be great even on brand new ones as there are sellers that buy them in massive numbers and run full time businesses related to selling these DVDs. Make sure that you see the feedback score of a seller to make sure that the person is a genuine seller. A good feedback score is an indication that the seller is reliable and will deliver what he or she promises.
In Store Specials
You will always find some sales in stores. These are generally for DVDs that are not selling well or leftover stock that needs to be moved to make more space for new incoming stock. You can pick some great deals from here.