This isn’t the reason, but could be a reasonable explanation:
These dongles are only necessary for things like docks to make their fixed connector work with a new device. So apple won’t sell many of them, therefore they have to charge a lot to make up for low volume.
Yes, because you can just buy a usb-c to usb-c for cheaper. You could get a 15 foot one for this price
This isn’t the reason, but could be a reasonable explanation:
These dongles are only necessary for things like docks to make their fixed connector work with a new device. So apple won’t sell many of them, therefore they have to charge a lot to make up for low volume.