If you use my Plugin SkinPlus and Plugin Google Maps into your Virtual Tour read this
Starting June 11, 2018, a new pay as you go pricing plan will go into effect for Maps, Routes, and Places. This new plan gives you more flexibility and control over how you use our APIs: You can use as much or as little as you need and only pay for what you use each month. We would also like to highlight that beginning June 11th, we are changing the pricing for our Maps, Routes, and Places products. You can review the pricing table and see the API-specific Billing Changes page for more information. Premium Plan customers will transition to the new pricing plan when their current contract expires.
All info here : https://cloud.google.com/maps-platform/user-guide/pricing-changes/