USPS postage costs depend on the size and weight of the item being mailed.
General postage rates can be found on the USPS site.
USPS rewards planning and proper organization, and provides discounts for adhering to their requirements. Drake Postal Operations takes advantage of these discounts by utilizing a partnership with Mail Services, LLC to imprint barcodes on daily mail in white or light-colored #10 envelopes or white large envelopes (9"x12") to save almost $4,000 per year.