I just received disk depot's mail shot and they've got a cracking offer on at the moment. The ritek disks (which are one of the best disks in my opinion) are reduced by a £1 to only £6.50. If you're needing a whole box of 600 then you'll get free shipping.
600 disks is too much for me, but I've bought a few packs at £6.50
p&p from £4.05