There are different classes of licenses for Cpanel & WHM (one license for both). If you plan to install Cpanel & WHM on a virtual private server (virtual dedicated server) the price for a monthly license is $20. For a yearly license it is $200 dollars. For a dedicated stand alone server the price starts at $45 per month. You can also pay for a 1 year license for $425 dollars, a 2 year license for $775 dollars, or a 3 year license for $1075 dollars.
If you need multiple licenses Cpanel offers volume discounts. For yearly licenses Cpanel offers a 10% off for 2-4 licenses, 20% off for 5-14 licenses, and 25% off for 15+ licenses. The pricing information for Cpanel is valid as of November of 2015.