This coin is currently for sale as an unpublished type with an asking price of $742.22 (shipping is another $40). Though it is a neat coin, it is still unofficial.
"Constantine I The Great
Arelate (Arles) Mint 326-327 AD
Obverse: CONSTANTINVS AVG Laureate head right
Reverse: VIRTVS AVGG Campgate with seven stone layers, four turrets and two open doors; PARL(dot) in exergue
References: RIC -, LRBC Unpublished, Extremely Rare
Size: 19mm, 2.86g
Professional Numismatic Notes: About EF and an exergue that's listed in neither RIC nor LRBC! Extremely rare and seems to be unpublished!"