Note that the Arduino IDE also has been developed at some expense. If you are open-source, then you should allow contributors as for the IDE. Open source makes sense. Charging for a particular platform is not consistent with the open-source philosophy.
And, I might add, the posting throttle of once every five minutes makes it hard to achieve the 100 post limit. Who thought this was a good idea? And why?
Joseph M. Newcomer, PhD (ret)