Don’t know whether it has been said or not, and it’s only really mundane stuff, but Sainsburys seem to have some cheap bike related stuff right now.

Primarily inner tubes for £1.99 each, tyre levers 3 for 99p, LED lights (more the type to be seen with, not to see with) for 99p for the front, or £1.19 for the rear including AAA batteries, Bottle cages and bottles etc. All perfectly usable anyway!