I'm going to take a guess: Zeno. It looks like it could be his monogram on the reverse, and you find a lot of his AE4s that are so worn as to be unreadable save for the monogram. Leo is also a possibility. At any rate: very late Roman, toward the end of the empire.
Can you see any letters above the N? If you can't, all I can tell is: Late Roman Bronze, Nummus 5th Century
I really can't make out any of the legend on the obverse, but AE4s of Leo are very common in this grade. Maybe a $20 coin, if that. I'd pay $5, but I don't like coins in this low of a grade, plus I'm a cheapskate.