I'm actually in the same situation only I'm the one looking to buy!!
The vendor bought the house and paid no stamp duty, but now wants to sell it. He's looking for €353k (2 bed apartment in lucan village). However if I purchase this property I'll be caught out with stamp of €10.5k, whereas all the other apartments were bought new from the builder and at a cheaper price. Do you think I'm crazy to buy it with stamp of that much as it's a new apartment, but was never lived in!!!!