Really pays to compare...
Oyster Bay Sauvignon Blanc white wine:
O'Briens - c. EUR13
JCs Swords - special offer of EUR9.99
Dunnes Stores, Newry - STG8.99
Sainsbury's, Newry STG5.92!!!
Also, someone who lives in Newry recommends Tesco's in Bannbridge over Newry.
I was kinda skeptical of the savings and the cost of travelling up North, combined with the time it takes, but I did a few trips over the Christmas period and am now a convert to NI shopping. Maybe a trip once a fortnight for the basics.