At the end of the day, buyer pays one way or the other, they can pay to buy and you then do not get paid the postage, or they pay you and you buy the postage.
Buyer pays means just that, even with free postage cost is still in the price. I think what you are looking for is BUYER buys postage and then you receive the label, and just the sale price, but as ebay frequently miscalculates the cost of postage, could leave you having to buy new labels.
In my opinion it is always best for seller to be in control of postage, not buyer, not ebay.
