If Gunns run out then there seems to be a Jessops in Dundalk. You can order DDX via the Jessops online ordering and have it delivered to the shop of your choice. Might have to wait a few days for delivery and OK it's a bit of a car journey but the way things are with the £ to the euro, you can probably pay for the fuel by doing a weekly shop as well. The BBC reporter over here, Mark Simpson, an Ulsterman, was sent back to N Ireland and then went shopping in both the North and the South for the same basket of goods. What cost the equivalent of over £11 in the South was only just over £8 in the North! A weekly shopping basket must save a fortune.
What's that phrase? Oh yes, the luck of the Irish.