Reverse engineer a classified site loophole

Ok so recently I discovered someone using a loophole in a popular US based classified ad website. I have been following it extensively and have been testing it every which way I can to replicate results unsuccessfully, I have tons of data on what works and what does not and videos made to explain everything. I need someone who is familiar with post / get requests with some if not LOT of reverse engineering methods. Based on my findings its not an exploit but possibly a form field manipulation. I will be offering generous bonus for one who finds this solution , also due to nature of the project I will need to chat will coders on skype to explain full details, if you are not flexible there, do not bid. Jquery knowledge might come in handy Alright you magnificent bastards, I am uppping my bid on this project, PLUS bonus ## Deliverables php jquery craigslist xss cross site