Well if you feel disappointed at not being ripped off online before, join ebay and you can lose alot of money and stuff. It is like buying in the blind, sometimes. Then gunbroker has lots of guns with poor dark fuzzy pictures that someone wants you to send them lots of money for. So why would he risk his online identity for 150$ stock, because he can change it any time. Good luck with that but I suspect you have sent your stock out into a black hole. Maybe you can contact his local PD online and make a fraud complaint but it would cost you in time and money as much as a new stock to even try to get it back, I suspect. So it is an expensive lesson. I have a few of those too.
Your gun is like your nose, it is just wrong for someone else to pick it for you!