The price of the stamps rise after some years, you need to check on the usps.gov website for the exact prices of the postage stamps. More Info: https://goo.gl/hMaHrt
It depends on the weight of the package, which can also be affected by the kind of packaging eg, envelope or jiffy bag. It also depends on exactly where you live and whether the regulations have changed. The only way to be sure is to go to your nearest post office and ask to have the packet weighed - you can ask them if there is a standard price for next time.