The problem is how much would people pay? Not very many negatives are left. We would need to charge at least $2 a neg I think. I doubt we'd leave more than say 500 a month. 500 is an aweful lot of negs since 98% of transactions seem to go well. But for all I know really it's only 95% but 3% are afraid to leave it. Would you really be willing to pay $2 to leave a neg?
I'll tell you though I'm pretty pissed off right now. I just had this happen to me a few days ago. A seller never sent the item. I waited 2 months and they said they sent it again after 1 month. So I waited. It never came and they would not give me delivery confirmation. It was a $10 item. So I left neg. 2 days later I get one back saying I'm a theif and that they had delivery confirmation. A total fabrication. They never had delivery conf, ever. If they did then why not give me the confirmation # when I asked for it several times.
So anyways the moral of the story is that had I waited and sniped a negative then I wouldnt have got that unjust retalitory feedback from a liar and the true theif. The only reason I didnt get my money back from paypal was because I trusted them to send the item the second time. Of course no delivery confirmation that either.
If you think people would pay $2.50, and there would be enough people leaving negs then it would be worth it. I think we'd need to leave at least 400 negs a month for it to worth it to us. Because we'd have to program it, test it, and keep it updated with eBay, give support etc.