Formatting energy costs with 2 fixed decimals

when I try the code below in developer tools → template editor, the result ist correct, for example 5,30 Euro. But in the dashboard and in the developer tools → state, the value is 5,3. The 0 ist missing.
Can you help me please?

  • sensor:
    - name: “Stromkosten heute”
    unique_id: Stromkosten_heute
    unit_of_measurement: Euro
    state: >-
    (((states(‘sensor.Energie_pro_tag’))|float *0.3187)|round(2))

0.3187 is the price for one kWh. The calculation is correct. But when the result is 5,3 Euro, the 0 is missing. It should be 5,30 Euro.