I ship at the PO virtually every day, either from NY or the office on Rainbow in Las Vegas. It all depends on who you get. If I send a bubble wrap with one or two chips, I know as soon as I walk in, which clerk will charge me $2.54 and which one will charge me $1.20. My advice is to strike up a conversation with the clerk, and you are more likely to get the "good guy" rate. One time I got a new person, who had to ask his colleagues if my package was. "Flat" or a "Parcel". One came over, bent my envelope, proclaimed it a "Flat", and I was charged $1.20.