If you're in Shankill, then you're not too far from Gorey, Co. Wexford - Redmond's garden supplies (not plants, just paving and ornaments) is about 3 miles north of Gorey on the N11.
I got beautiful large slabs of Donegal stone for a crazy paved patio for €15 per sq yd. Another centre in Camolin was charging €42 per sq yd for exactly the same stone.