Depends when in the day you cook - gas generally costs around 6p per Kilowatt hour (KWh) and electricity around 12p per KWh, so basically, it is cheaper to cook using mains gas.
Definitely gas. You're simply converting fuel to heat, whereas the alternative is to convert fuel to electricity and then to heat, which costs far more.
My village has no gas supply, hence I use electricity, and I'm used to that. However, I'm moving soon to a house where I have the choice. Don't know what to choose really.
so versatile, naomi....the one here is over 50 years old, water heated, two ovens, two major rings and does the roasting and a lot of the ring cooking. About £65 a month plus an annual service and a chimney flue clean.