A fallacy that consists in defending/attacking a conclusion on the basis of the amount of time, effort, money or manpower employed to reach such a conclusion, rather than its intrinsical rigor or soundness. For example, refusing to reject a theory that is clearly refuted by evidence just because such theory has a very long history and/or a vast amount of scientific literature behind its back, while the counter-evidence required very little effort to be obtained and/or can be exposed in just a few lines.
In reality, the hierarchical nature of science make it so that centuries of work can be easily wiped out by one moment of research, in case the latter pertains to a higher standard of proof than the former. One good study can refute dozens of bad or outdated ones.