well you cannot, but at the end of the day it is upto the seller to sell the item, i have just about given up in trying to sell stuff on eBay i have 2 things for sale, but more and more crap from buyers, who want every thing for Nowt but will then sell it again in a shop were you will not be offered a penny off , but you are correct they cannot have it both ways , expect yoou to sell the stuff you have put on here cheaper on eBay, the fees are stupid , we all know ebay is a farce when it is phone a friend time , as he can then retract his bid before the first 12 hrs ,
i have never done it and never will , a reserve price on eBay costs a packet , the only option left to the seller is to say the item is damaged and return the winners money,
eBay will not allow you to end auction listing , only a buy it now, but you can change the price until no one will bid , provided no one has bid,
i have seen one guy get so pissed off with eBay tit's he started the auction at 99p and put £700 post ,all i can think of if you are not happy with the price dont bid, if it says buy now £500 dont offer £400, and dont say you were going to buy an amp and yours will do and offer £600 off the asking price because it is cash , in a eBay email as they watch out for things like that,
the seller will end up with the fee regardless, if is cheaper on here then ebay talk to the guy you may get the deal you want, at the end of the day we all want abargain ,hell if it is that much of a bargain go an pick it up and pay the man , and not put it is a con