Only pain with USB is high cost of VID(only 5000$ per year).
It's $4000 per year to become a member of USB-IF. There are only about 500 members. The $5000 is a one-time fee to purchase the Vendor ID (VID). With it the purchaser receives 65535 Product IDs to use any way he/she wants.

For playing, though, you could enter just about any number you want for VID & PID. Just don't sell a product doing that. DT used numbers in his examples. Not sure if he paid the fees or borrowed those numbers. And yes, Microchip has a program where you can request one of their VID/PIDs when you are using their components in your product.