You only pay for the servers you've upgraded to the paid plan. For example, if you have three servers but only upgrade two of them, the cost will be $20/month.
We don't have a trial of our paid plan but you can use our free plan for as long as you need.
There's no limit to the number of servers you can have on the free plan.
You can upgrade or downgrade a server at any time.
Yes. You can upgrade or downgrade individual servers.
That server will only be billed for part of the month.
That server will only be billed for the time it was on the paid plan.
Your card will be charged after each month has ended.
Simply delete the servers from your account.