Assuming it really was drawing 120W, that's about 1000kWh for the year, so €300 at this year's unusually high prices, €150 in a more typical year, and probably

Assuming it really was drawing 120W, that's about 1000kWh for the year, so €300 at this year's unusually high prices, €150 in a more typical year, and probably half of that will be offset by reduced heating costs.