Variable pricing is the practice of selling the same product at different price levels to different consumers. When you take an airplane trip sometime, quiz the people sitting around you about what they paid for their tickets. Many airlines operate flights with 20+ pricing buckets, an indiciation of their reliance on revenue yield management for profitability.
A price that may fluctuate over the life of a contract, sometimes tied to a market index (see Market-based or index pricing).
A pricing strategy wherein a retailer alters its prices to coincide with fluctuations in costs or consumer demand.