Yes, some charges will be incurred as the kubernetes collector uses up CPU/Memory when deployed. Typically, 0.5-1 for CPU, and 500MB-1GB Memory is seen which factors in a percent of cost of the whole node.
Network charges will also apply. However, this varies depending on the number of workloads running on the cluster. Lesser number of pods/deployments/jobs etc, lesser network charges.
CloudHealth posts data every 15 minutes for a total of 96 times a day.