Just went on a coin shopping trip in celebration of my birthday; bought a few more coins for my OFEC attempt (Turks and Caicos, Sarawak, Crimea), a new Romanian type, some random low-grade 18th century stuff - and this weird ancient.
Seller said that it was probably Augustus, but wasn't quite sure either; I decided that the chance of it really being Augustus was worth the $9 I paid, and it was clearly an interesting Roman coin anyway.


Obverse: portrait to right, illegible-looking legend around (the start kind of looks like CAES, and there's a few other just visible letters, but I can't read anything definitely).
Reverse: galley (to left, I think, but I'm not sure what the front part is), two-line legend below, traces of possible legend above.
The size is 26 by 24 mm; can't give the weight (misplaced my ruler).
I can't make sense of the letters under the galley at all. If they're Latin, they appear to be complete gibberish (but could be abbreviations); if they're Greek, they kind of look like ΑΙΓΕΛΙΩΝ, but I have no idea what it could mean (or even whether I'm reading them correctly).
I checked the Wildwinds listings for Augustus, Tiberius, Caligula, Claudius, Trajan, and Hadrian, and did not stumble on any matches. I might have missed them, however (or the coin could be a type not in Wildwinds, and/or not of any of those emperors).
EDIT: some googling while finalizing this post provided
this almost certain match - Aigeai, Cilicia, for Tranquilina.
(Reverse fits so exactly it might well be a die match; obverse is too damaged to be sure either way.)
Still a nice purchase for $9, I guess? Might as well post it here anyway.