No-one has replied to my post below so I phoned up southern electric and they said the rough cost of heating one bed small flat with storage heaters will be about £50 per month on superdeal.
rate 1 = 11p rate 2 = 6p rate 3 = 4p
scottish power came out best on comparision but phoned them and they said £60 per month on
rate 1 = 13.25 (first 225kh) I'm not sure if kh is alot! second rate after used first bit is 7.10p and rate 3 for night time is 3.43p
now i am really confused but dont know which will work out cheapest and to me £50-£60 sounds alot for tiny flat for 1 person