When subscribing, you have a 5 days trial period. During this period, you benefit from a free $60.00 credit. When the trial is over or if you exceed the $60.00 free credit, your will be charged as your subscription plan.
For more information regarding the trial, please refer to Google Cloud Platform Free Tier page.
This trial only applies to Genymotion (Software), not GCP service (Infrastructure). In other words, you will be charged with Google Compute Engine Costs even during the trial.
For more information regarding Google Compute Engine Costs, please refer to Google pricing page.
Subscription is monthly and includes:
Genymotion usage fees: pricing applies on actual time consumption (pay-as-you-go).
Google Compute Engine Costs: pricing depends on the instance type (CPU, RAM) and storage size. This price is fixed on a monthly basis and applies at any time (even during the trial).
For more information or for an estimation, please visit Google marketplace here.
For billing issues and disputes, please refer to I have been charged incorrectly by my cloud provider; how can I request a refund?