Cheap Lamp Shade at Homebase - £1.99 White Paper Shade
Homebase has got cheap lamp shades selling at £1.99 with free click and collect. These are for the white paper domes, or circle shades.
So far, although I'm still looking, these are the cheapest I can find them. Habitat is selling them for £3.
This one is 30cm x 30cm, and is meant to be using as a ceiling light.
Hope it helps for anyone looking for cheap lamp shades.