There are no fees associated with the basic MPLAB® Harmony framework. The basic framework includes Microchip's USB, TCP/IP, Graphics and all other software found in the MPLAB® Harmony download file.
Most MPLAB Harmony compliant software from third-parties does have some cost associated with it. Some of this software can be purchased at microchipDIRECT. Please contact these companies directly for pricing details.
Microchip Technology acquires Atmel