I've just been in JJB Sport in Liverpool and they are selling Nike Pro Vent tops for £5 as part of their 'Credit Crunch Sale'.
They had a load in all different sizes and colours in a combination of vest, long sleeve and short sleeve. They were all £5 which is a total steal... I usually have to pay a minimum of £12 for a long sleeve.
* Body fitting performance base layer
* Dri-Fit fabric: helps keep you comfortable and dry by moving perspiration from your skin to the outside for rapid evaporation
* 74% polyester / 14% nylon / 12% spandex
* Seamless with a lightweight tubular construction
* Flat stitching for reduced friction
* Breathable mesh panels