 It's going to cost you a little more to send a letter starting later on this month. The United States Postal Service says stamps will sell for 73 cents apiece starting July 14th, which is up a nickel from the current price. Other postage costs are going up, too. That will include postcards and metered letter rates. The increases are part of a decade-long financial outline that the USPS is calling the Delivering for America plan.