how much does a first class us postage stamp cost
1 USPS Tracking when purchased online will cost $0.36 in 2015, compared to $0.23 in 2014. 2  Postage for First Class Mail International Letters (1 oz.) and postcards will increase by five cents from $1.15 to $1.20. 3  First Class Package International Service will see an increase of 7.2% in 2015. The discounted âMetered Mailâ category for First Class Mail Letters (1 oz.), which includes online postage providers and postage meters, will increase from $0.48 to $0.485 in 2015.