You usually compare them to common build options and see if it tops that. Like for example a common hammerdin helm is Harlequin Crest. A good paladin circlet will have to beat that in some regard like offering resists and FCR and a few other mods to offset the loss the HP/MP/MF/10% DR and the +2 to skills will have to match. But yes the teleport charges and the mana were good mods.First of all, is it any good? And second of all, if so, what kind of build would it suit? I'm still struggling to identify what makes a good rare.
And not be off-topic -I found myself a Shako again. I'll need another character with the socket quest though.