One does not expect genuine examples of this coin to be selling on eBay for such a low price. But what do I know? I'm sure he's an honest seller who also likes to sell Otho denarii for $26.55.
I saw that last week and spent some time examining it against known fakes and concluded that it was a heavily "aged" modern fake, matching several examples in FAC's database.
OMZ! He has selling the funniest Athens owl deka, with a chubby Athena on it!!! The coins are pretty obvious, the caligula and a couple others not so much, but worth a look for laughs...sadly he has a lot of buyers lined up for the garbage he is selling.
And wow! High-grade, well-patinated Matidia sestertius from the same dealer for less than $200! SMH (and that's not a Heraclea mint mark, either!).
If you want to avoid eBay fakes, one tool is to belong to the CoinForgeryDiscussionList https://groups.yahoo.com/neo/groups/CoinForgeryDiscussionList/info?yguid=116957790 Another is to avoid blacklisted sellers: http://augustuscoins.com/ed/fakesellers.html and the important Forum list http://www.forumancientcoins.com/fakes/index.php and http://www.lateromanbronzecoinforum.com/index.php?topic=1218.0
I saw that one as well and the lighting/photograph was not good enough for me to determine authenticity. However, after looking at the rest of his coins, I concluded it's likely a fake...
I would observe that one would not expect genuine examples of this coin to be selling on any venue for that price. That observation alone is sufficient to mark this coin as counterfeit. Inexperienced/unknowledgeable/unsophisticated owners of ancient coins will tend to price those coins at ridiculously high prices. Thus: Any time an ancient coin is listed for a ridiculously low price, that coin is counterfeit. Period.