"I probably would have bought it and asked them to lower their shipping costs.."
Speaking as a sometime ebay seller, nothing ticks me off more than a buyer who attempts to negotiate shipping costs AFTER a purchase. The terms of sale, including shipping, are right there for you to see. If you buy, you agree to those terms. To try to change the terms, with the unspoken threat that you might leave negative feedback if the seller does not cave in, is not fair. If you really need a shipping discount, get a firm commitment BEFORE you bid.