Systems and methods for conducting multi-item auctions for complex goods that allows bidders to specify budget constraints is disclosed. The system includes a server, a network, a plurality of trader systems and a data store unit. The system allows bidders to work effectively with limited budgets. The server includes an allocation unit performs a sealed-bid auction that enables bidding without the risk of going over budget, and thus, the present invention encourages bidders to place more and higher bids. Sellers will therefore receive higher prices and goods are more likely to be efficiently assigned.