Lately I have you pay a rate and then I put the cash change in with your envelope with the item. Otherwise I can't guestimate and I loose a lot of dollars because postage goes up and up more it seams. Have you noticed that as well? Postage is costing me so much more than it did a few months a go. They no longer take anything under 6 in. and they charge exorbitantly for small items that weigh under an ounce. Bewildered.