Default startprice Gas / Electro

Hi HA users.
I use HA to show me the daily use and cost of electro, gas and water.
I know the price for gas / m3, for electro / kWh and for water / 1000l.
But I want to add daily the extra standard cost for the network use.

Example :

I used 20 m3 gas at a price of 1.20 euro.
That is 24 euro.
The networkcost are 0.96 euro each day.
So I want HA to show me a price of 24 + 0.96 = 24.96 euro.

Is this possible in HA.