In fact, I agree with the donationware idea. Not that I think it would bring back much money, but it sure would give the chance to some people to feel they have contributed in some way to the plug. It leaves a choice to those who are using the plug to show their appreciation through remuneration if they want to.
But still, I don't believe a person creating plugs (which is a hobby) should be able to charge money for his/her plugs if he/she wanted. Charging money usually means we think highly of our work, and I don't know many people who wouldn't overprice.
Let me explain how I would judge if something is overpriced.
Have a look at EVN: 30$ for one engine, 6 storylines, one wide galaxy,
The thing many people will ignore/forget is the engine when pricing. They compare the storylines, the systems, the weapons, the graphics, but they forget the main thing: what holds it all together.
For this reason, I think that any kind of plug should be priced (if necessary) at 10$ maximum. This means that only something that could be put at a similar or higher level than EVN could be priced 10$.
(note: any plug that changes the engine with Matt Burch's permission would probably then be able to go up to 15$)
So, anyway, back to the matters at hand.
Economically speaking, any work has the right to be remunerated. Ethically and legally speaking, something started with the idea of doing it for free and kept as a hobby should not suddenly become something people pay for in the eyes of the creator of that something. It's just not right.
To use the legal point of view, let's say (I'm using easy and understandable terms here, no worries) that you mentally sign a contract with the community once you start working on the plug. This mental contract is based on the agreement of both parties, yourself and the community. It is regarded as a true contract, based on this agreement (the community can agree silently here).
This mental contract says: "I will do my best to bring you, the community, this plug. I will not charge you for it, because you have already offered me the chance to start work on it".
A contract cannot be changed unilaterally by yourself in this case. The only party here to be allowed to change that contract alone is the community. The community can say "This is so good that I will pay you for this!". Perfectly legal. But you cannot say "This is so good that you will pay me for this!". It's illegal.
Another way to change this contract is by getting a third party involved, ASW in this case. They can create a new contract with you that will destroy the mental one. Perfectly legal.
But, I repeat, you cannot yourself decide to charge people for that something you started with the idea of making it free for the community.
You might object, for example with the idea of a band that starts by playing music for free, and then starts asking money for gigs and albums. Well, sorry to burst your bubble, but it doesn't work that way.
me thinks about the legal problem for ten-twenty minutes before solving it
The community the plug-in developer "works" for is a very well determined party. When musicians decide to write songs/play them, the public is not determined at all. There is therefore no contract.
If a band is formed for one specific goal, there is a contract between them and the audience related to their goal. They cannot change their policy without ending the contract that was born, and that means including the audience in the talks.
My band was formed with the idea of playing for the school public. After almost two years, I wanted to organise a big concert for which we would ask 2 Euros per entry. The school prefect refused flat out. The only way I was to ask for money was if we changed our "contract", whereby we got the "concert hall" for free. I couldn't ask for money if I didn't pay
Hope you understand this. If not, do ask simpler explanations