You might do better just hitting local garage sales or a local dealer if you have one. Occasionally, the latter get used bows on consignment for about the same amount of money as ebay's quoting.
The advantage over mailorder or the like is you can actually examine or handle the bow. It doesn't hurt to shoot it before buying either. If you're on a tight budget, you probably can't afford to waste money no matter how cheap the asking price.
Don't worry about the man with one gun. He probably just lost the other one. =O)