If you put the number in context, I think it would make more sense. As most said, 5,000 = Fifty Hundred. You seem to want to avoid using 5,000 for whatever reason though. I just don't understand why. In the U.S., the term fifty-hundred is generally wrong and I'm guessing most people who heard someone use this expression would probably conclude that the individual is not very smart. I can't think of any sentence where one would use the term fifty-hundred over five thousand. "Scrooge sorted his money at his desk. He made fifty hundred piles." That's about one of the only ways I can think of to use the term fifty hundred and it's pretty horrible. In conclusion, turning a generally unaccepted number into a numeric form isn't very easy. Just use 5,000 instead.
