I'd be surprised with the current gulf between the fuel prices....
Those of us without a gas supply this is by far the best heating solution available.
One of those situations where you would need to calculate the actual costs and usage Sadly I don't have the brain to do that
The Panasonic 5kw I looked at - Nominal heating capacity 5.8kw, Nominal power input 1.44kw.
https://www.aircon.panasonic.eu/GB_en/product/etherea-inverter-silver-r32/