We all make mistakes...but twice in the same auction and both are mules from the same mint?
even though these two at HJB were advertised as mules, they are not.
The first --
"Maximianus, Mule with Reverse Meant for Diocletian; 286-305 AD, Carthage, c. 303 AD, Follis, 9.35g. Mule, coupling obverse of Maximian, RIC-33b, with reverse meant for Diocletian, RIC-33a. Obv: IMP MAXIMIANVS P F AVG Large laureate head r. Rx: SALVIS AVGG ET CAESS FEL KART Carthage standing r., head l., holding fruits in both hands, A in exergue, I in l. field. Maximian's reverse in this issue should be from officina B, with H for "Herculean" in left field. On our coin an obverse die of Maximian has wrongly been coupled with a reverse die meant for Diocletian, from officina A and with I for "Jovian" in left field. A rare mule, possibly unpublished; not in RIC or in Lech Stepniewski's website "Not in RIC".. VF"
This coin is actually Galerius (Carthage 43a) and someone bought if for $300.
The second coin--
"Maximinus II as Caesar, Mule with Reverse Intended for Galerius as Augustus; 305-308 AD, Carthage, 306 AD, Follis, 9.98g. Cf. for obv. RIC-44a, but for rev. RIC-43a, an incorrect combination (mule). Obv: GAL VAL MAXIMINVS NOB CAES Laureate head r. Rx: SALVIS AVGG ET CAESS FEL KART Carthage standing r., head l., holding fruits in both hands, I in l. field, A in exergue. A rare and apparently unpublished mule, not in RIC or in Lech Stepniewski's "Not in RIC" website, which couples an obverse die of Maximinus II as Caesar with a reverse die meant for Galerius as Augustus in the same issue. In this issue, each officina struck for only one emperor, so Maximinus' coins should all have been marked with a Γ in reverse exergue (officina 3), not with an A as on our coin (officina 1), showing that this reverse die in was intended for the emperor Galerius. The I in reverse field indicates that Galerius was a Jovian emperor; the same rank applied to Maximinus Caesar also, whereas the coins of the other two rulers in the issue, Severus II as Augustus and Constantine I as Caesar, were marked with an H indicating the subordinate Herculian rank.. VF"
This coin is a perfectly normal Carthage 40b with delta in the exergue. Maximinus was most junior, so he had the last workshop for this issue.