eBay Shipping Costs

Don't you just hate it when someone is clearly over-charging for postage and packing? Sure, I know that it takes precious time to pack, and uses up materials that costs money (have you seen the price of bubblewrap and strong envelopes these days?!) but when something is small AND light in weight and apparently costs the equivalent of £12 to send, when you know it would cost less than half that, it's kinda annoying. But what can you do? Query it and risk the wrath of the vendor, or else refuse to pay it and get a negative feedback? Solutions on a postcard, please!