It all depends upon your useage really. I cook quite a lot when in the Canaries and I started with a two ring electric hob which was inefficient. I bought a nice gas hob for 110 euros and and was given an 11kilo gas bottle. It cost me last year about 15.50 euros and it has lasted a whole year with daily use over a 6 month period. Before leaving very recently I exchanged for a refill bottle and cost me about 16.50. The price of this size bottle is regulated by the Spanish state. If you use very little gas maybe don’t bother because electricity is not expensive -the greater part of my bill is the damned potencia charge. However standing charges are creeping back in UK now ! If you are with Iberdrola you can use the ‘con discriminacion’ tariff for electricity that allows 12 hrs midnight to noon at about 0.7 cents a unit and 21.cents for the other 12 hours.