Hello @Mathieu G , Thanks for using Microsoft Q&A Platform.
Are you talking about the estimate displayed on the Azure portal under your resource pricing tier?
If this is the case, then you need not concern about this because when you create a resource under Standard pricing tier this will be shown default irrespective of your model usage (prebuilt/custom) as shown here for my resource.
It's important to note that it is just an estimate and may not reflect your actual usage or costs. To get a more accurate pricing estimate, you can use the Azure Pricing Calculator
Please refer to this page to learn about how to estimate the cost of processing pages using the Azure pricing calculator: https://learn.microsoft.com/en-us/azure/applied-ai-services/form-recognizer/how-to-guides/estimate-cost?view=form-recog-3.0.0
If you are still experiencing issues related to billing, I recommend that you raise a support request in the Azure portal. If you have a support plan, you can do this directly in the portal. If not, we can help you create a one-time free support ticket. Please let me know.
I hope this helps.
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