I had one of those last year, i was terrified beforehand but it was grand, didn't feel a thing. (it was €200 cheaper down the country than in dublin)
I was quoted €350 for it. The upside apparently is that my tooth is so badly damaged (popped a filling last year, tried to nurse the tooth through to January when I go to my annual checkup, lost a massive chunk of it at Christmas) that the nerve is dead s that's why my face isn't really fucking sore.
Edit: I don't mind the dentist at all. It's getting my hair cut that I hate