Challenge 2KW Upright Fan Heater at Sainsbury's Bramingham Park Store

Of course it is and it is horrible stuff. Electricity - 35p/kWh gas 10p/kwh
Whatever you do - you'll use certain amount of kWh to reheat your house - as you loose heat through the walls etc - you need to put that energy back. People have no idea what they're doing...

To be fair - gas boilers are at least 90% efficient these days. Sadly many houses have the heating pipes under the floor (no insulation mostly whatsoever so your hot heating pipes are exposed to cold air for no reason) and that's where they loose heat from the boiler. I removed everything from under the floor and invested in quality pipes and radiators and my savings were quite nice from the beginning. There's no chance that the electric heater will be cheaper than gas unless we're talking about air conditioners. (edited)

I'm assuming this is in a small, very well insulated room?

Yes you may. Saw 4 more on the shelf.