The savings aren't huge or anything but the key is that the delivery confirmation is free. I've been paying 60-70 cents for that on every package I've sent out through ebay. Add the small discount for buying postage online and I save around a buck or so per item. That might not seem like much but margins are pretty tight whenever I sell things. I finally worked out the math and the profit on the Petunia Pickle Bottom bags were less than what I had hoped after ebay/paypal fees were taken out. Fully a quarter of the profit was taken up by those fees. No wonder the only people to survive selling on ebay are those who sell in bulk. You're nickel and dimed to death and the only way to maintain a fair profit is to up the number of transactions.
Oh well. A penny saved is a penny earned.