I agree with retrochic and eddie - I sell on eBay, but don't offer free postage as I would have to boost the price of the item in order to cover the postage cost (usually, as retro says, about four quid). People who sell on auction or BIN for very low prices and free postage are probably those who buy and sell in bulk and can afford to take a loss on some items. Private buyers wouldn't do that, it's not worth selling under those circumstances - you might has well give the items to a charity shop.