Item creation. Help with Price

[Spoof]

Hey I was thinking of creating an Item for a game I am running but do not know the price/level of the item.

Amulet of Jade.

This amulet is made from jade, carved into the likeness of a flaming sun. It is held in place by a 5-fingered Onyx holder, the chain is made of pure silver.

Powers:
+4 to turn/rebuke undead
+2 to HD affected for turn checks
Grants 2 Greater Turning/ Rebuking per day.. (Cannot be used with divine feats)
Allows twice as many HD undead to be controlled as normal.

This Item was created for the use by Helronna, one of Madriel’s high clerics, during the Divine War, but was corrupted by Belsameth at the moment of its creation. Belsameth placed in the item the ability to control great legions of undead, a power that helped her servants in the war, but one in which limited its use for the clerics of Madriel. Since the creation of the first one of these items many were made, but the secret was lost during the war, and has yet to be rediscovered.

 

[Black Knight Irios]

I would say you need the spells Unhallow, Limited Wish, and don't know (no books at hand).

1st: determine the most costly power of the item
13x7x1000gp (limited wish) i think it is the most costly one
2nd: determine the 2nd most costly power
11x6x1000gp (unhallow) mutiply this product by 3/4
3rd: there should be one more power determine it and mutiply that product by 1/2
4th: add the 3 products together, pay half that anmount in gold and 1/25 of that in XP.
Your Item is done. Maybe yoe should rule that the caster has to be at least casterlvl 15 or 17. And the use of unhallow and limited wish means you must be able to cast divine and arcane spells. If you take the right domains as priest you can still do it and a powerful mage could emulate unhallow with a wish spell.
I hope I didn't confuse you and maybe you got some good idea.