Complex sentence: The reserve price may be "fixed" or "discretionary"-in the latter case, the decision to accept a bid is deferred to the auctioneer, who may accept a bid that is marginally below it.
Split into simpler sentences: The reserve price may be "fixed" or "discretionary". In the latter case, the decision to accept a bid is deferred to the auctioneer, who may accept a bid that is marginally below it.