The cost of a book of stamps, also known as a booklet of stamps or a stamp booklet, can vary depending on factors such as the country and the type of stamps included. In the United States, as of my last update in January 2022, a book of postage stamps typically contains 20 stamps and costs $11.00 USD.
However, it's essential to note that postal rates and stamp prices can change over time due to various factors such as inflation, changes in postal regulations, and adjustments by the postal service. Therefore, it's advisable to check with the postal service or visit their official website for the most current information on stamp prices in your country.