curl --request GET \
  --url https://api.paygentic.io/v0/billableMetrics/{id}/price/{subscriptionId} \
  --header 'Authorization: Bearer <token>'

{
  "id": "<string>",
  "object": "price",
  "billableMetricId": "<string>",
  "model": "standard",
  "invoiceDisplayName": "<string>",
  "properties": {
    "unitPrice": "<string>"
  },
  "createdAt": "2023-11-07T05:31:56Z",
  "updatedAt": "2023-11-07T05:31:56Z",
  "deletedAt": "2023-11-07T05:31:56Z"
}