Amazon Web Services marketizes its idle computing resources through its spot instances offer. These resources are offered through an auction-based scheme at extremely low prices. A running instance can be shutdown whenever the spot price rises above the user bid. Several challenges and opportunities emerge from this new computing paradigm. This work proposes for the first time a taxonomy on auction-based cloud computing resource provisioning, based on the study of the most relevant literature. The studied works are classified according to: (1) provider or user perspective, (2) problem solved, (3) optimization approach, (4) objective functions and (5) solution techniques. Finally, new prospective research subjects are identified and proposed for this promising research area.