Selldom allows you to buy and sell domains that are waiting silently in the dark, unused at your registrar after your 100th side-project pivot.
The service also includes a feature that tracks the price of all the TLDs at the main registrar. You can view it at https://selldom.io/prices/, and see the .com example at https://selldom.io/prices/.com! This is automated and doesn’t require any work!