"I get chips coming in and the postage is 45c, right from the postal meter at the USPS. What am I doing wrong?"

Pete; If you are using a bubble padded shipping bag for say ONE chip ... and the total weight is less than one ounce... the correct postage is .11¢ surcharge (for being oversize)added to the regular .34¢ postage. Total = .45¢

Multiply that, times hundreds of one chip packages ... and you've been paying WAY too much postage!!