The price of energy varies hourly in the Nord Pool energy exchange according to the prices of the Finnish market. You can check the current and upcoming energy prices in Nord Pool's website.
This hourly varying price is called spot price. Usually energy companies add their margin on top of the spot price, plus a fixed monthly fee. So, the energy price per kWh is the spot price plus the energy company's margin. The monthly fee is fixed and your energy consumption doesn't affect it.