Hi there,
Reads of Nassau Street in Dublin have a printshop and they charge €25.00 per 100 or €65.00 per 500. I think that's just printed on one-side.
Another place to try is
www.vistaprint.ie . Ignore their free business card offers - they print their own name on the back of the card. But you can get 250 one sided cards for €19.99 on matt or €29.99 on glossy. For two sided colour they seem to add another €15.
I used them a few years ago when I was in Australia and was happy with the result.
All the best,
Jennifer