1. A processor-implemented allocation method in a buyer-driven system in which conditional purchase offers are received and considered by or on behalf of a plurality of sellers, the conditional purchase offers each including: (1) a buyer-specified price for a good or service, (2) a payment identifier specifying a financial account to be used to pay for said good or service upon acceptance of a conditional purchase offer by a seller, and (3) authorization to charge said payment identifier for said good or service upon acceptance of a conditional purchase offer, comprising: identifying by the processor one of at least two sellers as a priority seller based on a processor-implemented priority metric, wherein identifying one of at least two sellers as a priority seller includes: determining a number of first look opportunities to satisfy conditional purchase offers due to the at least two sellers; determining a number of first look opportunities to satisfy conditional purchase offers given to the at least two sellers; identifying one of the at least two sellers with the largest deficiency between first look opportunities given and first look opportunities due as the priority seller; and providing the priority seller with a first look opportunity to satisfy a conditional purchase offer after receiving said buyer-specified price, payment identifier and authorization to charge said payment identifier for said good or service upon acceptance of the conditional purchase offer.