Sometimes there is very little rhyme or reason to prices realized on ancient coin auctions. Many areas are so niche that there may only be 2-5 people willing to drive a coin up to a "high" price (be that $50 for a special LRB or $500,000 for some piece worthy of a royal collection) if those people aren't present, the coin doesn't reach the price. Case in point, I was outbid on this exact Messalina coin back in a Triskeles auction in June, where it sold for over $350 before fees. Maybe the buyer didn't pay, or maybe they had a change of heart, because it came back up for auction again and I won it for almost $200 less the second time around.
...they are great coins...i'm going to get one or two of the Dioscuri coins this coming year ..if not b4 (less expensive, of course ^^)
..update:...i just purchased a C. Antestius with the doggie on front.....i'll post when it comes in..