Our 99p shop is doing Doff's Derris Dust and the J Arthur Bower boxed feeds. Wish I'd known before I bought 2 lots of derris at the garden centre a couple of weeks back at £4 each.
Also Woolies has all their gaerden stuff at half price. Walk-in greenhouse, staging, tools, pots, some plants left (e.g. 2 asparagus crowns, fruit bushes for £2.49).