I have used Createspace for years to distribute my DVD's. You can publish and sell your DVD programs easily using a online distributer. The following video from Videomaker shows you the advantages and briefly how to do it.
No duplication is necessary, they print them as they are ordered, and the products from Createspace are fantastic! They handle the credit cards, shipping and producing the product. You set your price to cover the cost of the aforementioned and the rest is your profit.
Check out Createspace and start distributing your DVDs today!