cooking all electric is it expensive?

[triplets]

After cooking with gas for over 30 years I am considering buying an electric oven, just worried it will really increase my electricity bill which is bad enough now. Advice needed!

I can't give direct comparison but I know our lekki bills are slightly below avg for our house-number of people. We only have electric cooking & we cook a lot (also use microwave & kettle a lot).