The Nike Store in Manchester Arndale is selling the running kit at sale prices.
Tees/LS Tees £12.50 (Lots of colours and sizes). Winter Tops £17.50 (I think it was)
Trackers/Tights (Didn't look at price)
I got a Clima-Fit jacket for £25 (only a few left).
There's also a clearance shop in the Barton Arcade (off St Annes square, M/c) selling mostly summer kit. Selling 2005 summer shoes at £30 to £40 pounds. Limited stock and sizes I think but you could get a bargain.
I got some Puma square-cut shorts with zipped pockets for £10.