Click Select metric. On the Select metric page, you can drag up the two lines in the middle of the screen to resize the lower section, making it easier to see the available metrics. Under Metrics, click Billing. Click Total Estimated Charge. Check USD. Click Select metric.

$10.$

By default, the Statistic field is set to Maximum, and the Period field is set to $6$ hours. In the Conditions section, the Threshold type is set to Static, and the Whenever Estimated Charge is$...$ field is set to Greater. Scroll to the bottom of the page to the than... field. Under Define the threshold value, type $5.$ As shown in Figure $1-23,$ this metric will trigger the alarm if charges exceed $$5$ once within six hours. Click Next.

Figure $1-23$