Estimating Google Maps APIs cost

[Fede Differ]

I have to develop a store locator, but I can not estimate the cost of the API call. More or less the estimated usage is half of the "Example 2: Store locator " at:

https://developers.google.com/maps/premium/calculate-credits

It will be enough free plan? If I have to pay, how much does one credit cost

Thanks for your help.