Azure IoT Hub pricing

Hi All,

I'm wondering how to design a solution where there are 8000 events per second from the devices and bidirectional communication is a must. A short calculation for the Azure IoT Hub:

**calculation
I followed this link for pricing https://azure.microsoft.com/nl-nl/pricing/details/iot-hub/

8000 messages/sec
691M messages/day

(691M / 6M) * $500 = $57600
**end calculation

How can I reduse costs in such a scenario. Use the IoT Hub and Event Hub side to side?

Regards,
Chris