[Inziladun]

If we look at the reason behind making a Ring of Power in the first place, I'd now be inclined to think Saruman's (assuming he did fashion it) just an ornament.

Sauron made the One and put his power into in order to control the wearers of the other Rings. In doing so, he also took the risk that if the One were ever destroyed, that part of his power would likewise be dissipated forever.

What motive would Saruman have had in trying do the same thing? He could not have exercised control in any special way. A ring created by him should not have led to any increase in his power, or in any of his native abilities. He was already an "inferior" of Sauron's in will and spiritual power, which is why he knew in order to challenge Sauron he must gain Sauron's Ring.

Really, making his own ring wouldn't seem to lead to any specific benefit for Saruman.