Go through Quidco and using their code which is valid until 30th November, you get £40 off a £100 spend on wine or champagne.
So they currently have Isla Negra at £3.99 a bottle, either add cases or individual wines, use the code to get the bottles at £2.74 including delivery.
EDIT! : Does not work with 50% Wines, which Isla Negra is, but change one of the bottles to a non-50% one, and Bob's your Uncle!!
DONT FORGET 8% QUICDO!!