Allow setting different prices based on the total number of members in the community and on when everyone signed up.
For example, the first 500 members lock in a free-forever rate, then for members 501st to 1000th the price per month is $10 per month, then anyone who joins between 1,000 and 2,000 locks in a $15 per month price etc.
The goal is to incentivize, motivate and reward people to join today instead of waiting and procrastinating. In order for that to work though, there must be an option to keep the current price for a specific group of users, so that any future price increases do not affect their rate. I believe the easiest way to implement this would be to order and filter the members based on when they joined and create certain member segments from the oldest to the newest.
However, I am confident that this would be an immensely valuable addition to the community platform that all HL community owners and their members would appreciate.