Well, I think that with the end of the $2's announced, a very large number of the later Thi-Crow and Bo-Thi notes were kept, including the low EGR's. Certainly, alot of them are frequently available.
The AUG is somewhat of an anomaly with the shuffling of signatures, which attracts extra attention from collectors. Also, it occurred early on in the series when (i suppose) fewer notes were kept. But a number of these AUG, AUH, etc.. have come to market recently, so I strongly doubt the $115 value is justified. Maybe someone has seen recent results but I thought it was closer to $50-$60 each.