@Chip Bennett -

I agree with your entire comment, with one minor exception... Richard Stallman is dogmatic about software being free, according to the "four freedoms". However, none of those four freedoms mention cost.

Likewise, nothing in the GPL prohibits someone from charging for the code they write or distribute. That's the perogative of the individual distributing GPL code. The only obligation is that the source code be provided at a reasonable distribution cost. For example, I could create a plugin and charge $1,000 for it. As long as I don't request another $1,000 just for the source code (unless it really costs $1,000 to make a copy), then I am fine by the GPL. Following this same logic, the clubs are well within the bounds of the license as long as they follow the distribution rules.

Do I think it unethical? No. Does it harm the community? Maybe. These folks do run the risk of alienating themselves from the larger WordPress community and the original plugin developers. This could make it more difficult for them and could lead to a fork, if the original developers refuse to sell newer versions to their plugins to the folks offering their services.