maxTotalPrice

The maximum amount per hour for On-Demand Instances that you're willing to pay.

If your fleet includes T instances that are configured as unlimited, and if their average CPU usage exceeds the baseline utilization, you will incur a charge for surplus credits. The MaxTotalPrice does not account for surplus credits, and, if you use surplus credits, your final cost might be higher than what you specified for MaxTotalPrice. For more information, see Surplus credits can incur charges in the Amazon EC2 User Guide.