I have have 2 suggestions for this. Both could be implemented but they may clash with one another.
Suggestion 1
I would not mind if players all donate towards the plot and once it reaches 150k/200k it starts. A notification will pop up that the plot has reached 50k, 100k, 150k/200k but a notification pops up once every half hour just so there is not much spam and it reminds us where it's at.
I believe at that price it will benefit the players that want to make it so that they can start things and also it's the same price to start a town. So if a new player pops into event world or someone working towards one they can either donate to speed it up or join in to try and win it. At that price I also don't think it will happen too often so it will have the rarity or specialty because we do not want it to be the main focus and take out lotto for people to try and make money.
Suggestion 2
I see events as a nice time for everyone to get together but I am not a fan if it was constantly spamming chat. For this suggestion have it so that someone pays $5 or have it as a pool so people can pay $1 or their desired amount then when it reaches $5 on the forums an Event game of 250k will start. Techs or Admins can change the event world every 2 weeks so that it is not repetitive each month.
(these are not set price it is just and example)
I like my second suggestion because events can still have that specialty of excitement and people will have that power to choose when it starts. I am certain that it is acceptable to the EULA because anyone can win it and no one gets an advantage over the other players. Then we will have money coming together and we can direct that to our techs that work on the server and hopefully we can get our plugins updated quicker and be on the right track.