Abstract: A method of transacting sales over a computerized network defines a first product desired to be purchased by a first purchaser; correlates in a first database record the first product and the first purchaser; further correlates in respective ones of a plurality of first database records the first product and respective ones of a plurality of second purchasers; issues an offer to a vendor to purchase the first product at a first offer price in a quantity responsive to the plurality of first database records; and consummates a transaction between the vendor and the first and second purchasers. Prior to performing the step of issuing an offer there is further provided the step of calculating a first commitment price, in response to a rate of performing the step of further correlating.