The Desert Banana Relay

A trader has 3,000 bananas at the edge of a desert. His camel must transport as many as possible to a market 1,000 miles away. The camel can carry no more than 1,000 bananas at once, and it eats one banana for every mile it walks, whether it is carrying a load or returning empty. The trader may create temporary banana caches anywhere along the route, and the camel may make as many trips between caches as needed. Bananas cannot be replaced, and only whole bananas count when the camel reaches the market. What is the greatest number of bananas that can be delivered?