I have a similar experience. I had bought two multi CD boxsets from a seller and after the auction was over asked if I could have a discount on the shipping rates, since sending the two boxsets together likely would not cost as much as sending them seperately. I had lost an auction on another, and the seller said that the only way he would offer a discount would be if I purchased an additional copy of the boxset I had lost. I was unhappy with that response, so when I got the boxsets I left a neutral explaining his offer, saying that I felt it was unfair. He retaliated with a negative saying I tried to change the deal after the auction ended. Of course I didn't, and if the seller had responded with a degree of kindness rather than with his mercenary-like tone, I likely would have cheerfully sent him the full requested shipping price.
I can understand that sellers will often get deadbeats trying to worm their way out of paying fair shipping prices, etc., but I don't feel my request was unreasonable, and I don't feel his retaliation was warranted.
Personally, I think the positive rating system is profoundly overused, and you should only give out a positive if the seller or buyer goes out of their way to do something special. If all you did was send the correct payment on time, and they sent the correct item on time, that ought to rate a neutral. You did what you said you would do.
