Make fixed price not change

Hello,

I am trying to setup a service to book a studio appointment where customers can choose the amount of time, and the amount of songs they want to record. I want to make it so that the Booking price increases when the amount of hours in the studio increases, but not the fixed charge. I want the fixed charge price to increase based on the amount of songs. The number of hours only changes the booking price. But the number of songs changes the booking price and the fixed charge. I want the number of songs to ONLY effect the fixed charge price and for it to have no impact on the booking price. Is this possible? If not do I need to just create separate products for the song quantity

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