Utterly confusing  I have sold 5 collectors  items recently, all the same dimensions and weight with 4 different postage prices, it seems one of the factors they use to determine postage is value of the sale, the sliding scale of buyer protection fees also adds considerable costs to the buyer  very off putting, small wonder high value items are being ignored when they add £5.00 or More to an item valued at £100.00 with postage fees can add £10.00 to an item