Here is a rare type that just sold for $889.39. Despite the rarity, I was surprised the price got so high. Below is the link to a topic about this type-
http://www.lateromanbronzecoinforum.com/index.php/topic,715.msg2106.html#msg2106Constantine I
A.D. 313- 315
21mm 3.5gm
IMP CONSTANTINVS PF AVG; bust left, laureate and cuirassed, spear across right shoulder, shield across left.
PROVIDENTIAE AVGG; Moneta standing on prow, holding cornucopiae, received by turreted Arles holding standard.
In ex. QARL
RIC VII Arles 30