Went into my local superdrug for some hairspray and other essentials and there is an offer on their own brand hair spray (and some other own brand selected hairstyling products like mouse and gel) at the moment.
Generally the normal sized hairspray is 88p, so two for £1.50 isn't the greatest saving but I noticed the VERY large extra firm hairspray tins (I think are 600ml) which are £1.66 normally were also in the 2 for £1.50 offer!! Go figure.
I checked at the counter first and it saved me £1.82! No idea who works these deals out but I am not complaining :o)
Online seems to only be the smaller tins and other own brand items in the offer, and you have to pay P&P which kinda ruins the saving for me.
Not sure when the end date is as it wasn't instore or online anywhere but in my experience they have changed offers every week to two weeks.