Methods and associated apparatus comprise, among other features, organizing previously acquired auction data into a plurality of sub-samples, each sub-sample comprising bid data associated with auctions having a common number of bidders, applying an inverse bid function to at least two sub-samples, pooling results from applying the inverse bid function to form a first pool, applying a direct bid function on the first pool to generate sample bids, matching bids from at least one sub-sample to the sample bids, and pooling results from the matching with the first pool to form a second pool.