Thought this might be useful, not actually a reduced price but compared to most places. very cheap.
£1.00 gets you 2.5ltr of concentrated screen wash.
I've been looking for a reasonable price for this, due to sub zero temp'. Most garages are well over a fiver, even most supermarkets charge £3.00 for the "ready to use stuff" so a great price at a great time.
Drive safe :-)
Couldn't see it on their website.