Honestly, it's pretty hard to find a low/no minimum supplier of DVDs. The price of even a new release DVD these days is so low, and the retail markup so slim, it's next to impossible to compete in them on any meaningful level (like, just looking at Amazon, the most popular thing under new releases is the Blu-Ray+DVD+Digital combo box of 'Rango' -- retail $45, Amazon price $20, Amazon Marketplace new from $15, used average $14.94 ... Ingram wholesale on this item is more than the Amazon price, and they're one of the best video suppliers in the US.)
What can you do with that kind of market? Movies are sold cheap to draw and keep customers, not to make money off of. Like games, they're pretty much a "loss leader" product for retailers, where they don't make much on them but make it up on ancillary sales of higher-profit stuff.
Used games are a better market for independent sellers, but to succeed at it you really need to have a broad selection -- which tends to imply volume orders from suppliers.
Not trying to be disheartening; this is a market to which people get naturally drawn, because the consumer demand is evident and it seems like money. But it's like the gas at a gas station -- most stations make squat on the gasoline, and are just praying you'll come in and get a candy bar while you're there so they can make rent. High demand does not always equal high profit, unfortunately.
"Failure is not when you fall down. Failure is when you don't get back up."