If you know anyone in the retails sector see if they could utilise a cash and carry for you.
Alternatively I've used a wine merchant up Cavan way that had some really good deals, last time we were just having a looksee and got about 10 bottles for aroudn the Eu75 mark. He imports from france so a lot of his wines might not be the recognised brands from our supermarkets, but a lot of them were very good quality. (PM me if you are interested and I'll get his number)
Why not try a farmers market, we've recently picked up some nice organic wines at our local market (held in Sonairte eco centre in Julianstown), they may be a little more expensive, but they are really nice and a little bit different.