Waitrose have Bahlsen Pick Up Biscuits currently on offer at 84p per pack.
This PDF below contains a sheet with nine 50p off vouchers making each pack purchased 34phttp://www.mediafire.com/download/a3d5ibu539dlk9y/9up_onepage.pdf
The website shows three types (Milk Choc, Dark Choc and Choco & Caramel) on offer although my Local (wimborne) only has milk and dark available.
The vouchers expire 30/8 so be quick, picked up 2 packs this morning so multiple vouchers accepted in one transaction
Thanks to Donuts123 for posting the voucher link previously