Stats are random, though the Nobleman's (holy) amulet is potentially one of the best in the game.
Save before you do the holy item sacrifice, then after choosing the amulet, quicksave before running your mouse cursor over it (or hitting the alt key) to identify it. That way you can quickload a few times to see what kind of stats you can get (save if you get something good).
If a few tries doesn't yield stats much better than what you have, you can reload the save before the sacrifice and try the sword or dagger.