What is the average cost to repair an Apple Pencil (USB-C)?

AFAIK, Apple does not repair their Apple Pencils. Depending on the issue, if it could be due to a manufacturing defect, and the Pencil is less than one year old, you may find that you can get a replacement for little or no cost to you.

these

forums are user helping other users like yourself, it's sort of going to a

physical apple store and asking other customers there advice

Apple Pencil repair - Apple Community

or reach out to apple using

 Get Support (apple.com)

And or

 Contact - Official Apple Support

And or

Contact - How to Contact Us - Apple

Or

Genius Bar Reservation and Apple

Support Options - Apple