Comment by esperent
> If I distribute GPLed software for a fee
Be aware of the difference between "software" and "source code". You can charge for people to use the app/program/website, but that doesn't mean you can charge for access to the source code and still call it open source.
You can't charge extra for GPL source code after distributing the software, but you can definitely restrict source access to the customers you sold the software to, although they can then redistribute it anyway.
If Blender Studio owns the copyright they can distribute it however they want though, presumably their free build isn't GPL; it just doesn't fit the spirit.