If every user has to pay the minimum price then the software would not be free software, by definition.

It would be a huge gamble if the "0$ version" (e.g. GitHub repo) gets more popular that anticipated and the one with the bigger price tag not growing accordingly and the whole risk calculation falls apart.

There is always the possibility to only offer the priced version, even if it is free software. Someone else could of course redistribute it and then it would be their responsibility. That would be a less convenient world.

An open question certainly also is, when it becomes a product? Source Code alone (inredients)? Or executable form (usable)?

The minimum price for the software can't be changed. It's open source. Once it's out you can't undo it. You will have users paying $0 to use it for what amounts to forever.