Next cheapest I could find was £4.99 at Argos.
Hope this helps someone!
Value pack of 8 Duracell AA general purpose alkaline batteries
Duracell PlusPower now has longer life compared to previous Duracell PlusPower batteries
Up to 40% more power (in digital cameras vs. Simply Duracell AA. Results vary by device)
High energy output, reliability and long shelf life
Duracell's DURALOCK technology means these batteries are guaranteed to stay powered for up to 10 years* when not being used.