Have been going into my locla Morrisons Store and they sell a 3 x twin packs of energy saving lights for only 20p.
They come in different watts 7w, 11w and 20w also availible as beyonet style or screw in ones.
One of these bulbs usauly cost around £1-£2 depenicng on make and shop but youre getting 6 bulbs for 20p!!
Managed to get 57 pairs for £3.80 hope my maths are right
All i need to say really