I wanted to add my voice to the concerns involving PayPal and the USPS. In the last two weeks I have received two notifications that what I shipped had underpaid postage. I've been doing this for almost 20 years. I use a scale. I don't agree with these charges, but there is nothing I can do, as PayPal locks the account until you pay. If this happens again, or I don't get an answer as to why these charges exist, I will look for other means of payment. Venmo, Square, something else that respects the customer, or at least gives you information as to why you are being charged.