Myself and some friends bought our chandeliers in Prague. They were very reasonable and packed so that we could take them as hand luggage on the plane.
Shannon Duty Free had Waterford Crystal chandeliers discounted by 20% recently. Have a look at the Waterford Crystal website.
Also try Uttermost Lighting in Mullingar.
try some DIY stores. B&Q liffey valley have a lovely selection, Atlantic Homecare & Homebase also do lighting & Woodies DIY.
Also Argos have a nice selection, eg. contemporary, vintage etc