[TheSpartacat]

Seed Parade website has 50% off if you spend £30
http://www.seedparade.co.uk

Postage cost is 95p.
They have a few discounted seeds in stock as well

[mumofstig]

50% offer is an awful lot of seeds, before you qualify for the 50% off, but the prices are low anyway

Have you used them before?

[Comfortably Numb]

Sounds like a good offer, but they only have a very restricted range of vegetable seeds by the looks of it.
 e.g only 2 varieties of cauliflower.