How are YouTrack Cloud estimated monthly charges calculated at checkout?

The checkout page shows the estimated cost if you have the maximum number of helpdesk agents and users included in the subscription.

The price you pay for the subscription will be based on your YouTrack usage. At the end of each month, we’ll charge you only for the maximum number of active user and agent accounts. With fewer active accounts, you’ll pay less. For example, if you don’t use helpdesk agents, you’ll be charged only for the maximum number of users.
You can use the calculator to work out the exact cost of your subscription.

For accurate information on your user and agent usage, check out the License Details menu item on the Global Settings page.