I was at my local Sainsbury's and they had a lot of offers on grooming products. They have the garnier fructis style putty/gum/clay/etc on offer (all ranges including: manga, surf, switch etc.)
I usually buy these at £2.30+ EACH! This offer is also online! Links to all below.
They also have BOGOF on the Loreal Studios hair styling products which is also a great offer. (Online showing as 2 for 1)
They also had quite a few shockwaves hairstyling products all priced at £2.