I think that's besides the point. This contract isn't "about the kids", it's about all Minecraft players and server administrators. If a server administrator feels they need to, or want to charge for some item or plugin, they should have the freedom to do so...
...after all, they aren't obligated to run a minecraft server in the first place, and if the only thing keeping the lights on is selling some in-game item, let it be.
...after all, they aren't obligated to run a minecraft server in the first place, and if the only thing keeping the lights on is selling some in-game item, let it be.