Breastplate of Command price breakdown

[atom crash]

I'm trying to breakdown the price and cost of the Breastplate of Command:

Breastplate of Command: This finely crafted +2 breastplate radiates a powerful aura of magic. When worn, the armor bestows a dignified and commanding aura upon its owner. The wearer gains a +2 competence bonus on all Charisma checks, including turning checks and Charisma-based skill checks. The wearer also gains a +2 competence bonus to his Leadership score. Friendly troops within 360 feet of the user become braver than normal. Since the effect arises in great part from the distinctiveness of the armor, the wearer cannot hide or conceal herself in any way and still have the effect function.

Strong enchantment; CL 15th; Craft Magic Arms and Armor, mass charm monster; Price 25,400 gp; Cost 10,975 gp + 850 XP.

The armor itself is worth 350 gp (masterwork breastplate) + 4000 gp (+2 armor) = 4350 gp. So is the Command function worth 21,050 gp?

The real question: how much would it cost to create a +2 mithril shirt of command? If the value of Command is 21, 050 gp, then it would be worth 100 gp (chain shirt) + 4000 gp (+2 armor) + 1000 gp (mithril) + 21,050 gp (Command) = 26150 gp.

But what is the cost to create? How is the cost to create the Breastplate of Command arrived at?

Thanks in advance for any help.

 

[The Amazing Dingo]

To figure the final cost I wouldn't have broken it down but would have rather just subtracted the Breastplate cost from the final cost to get 25,050 gp. After that I would have added the 100 gp for the chain shirt and 1,000 go for the mithril.

Yep, the same price. Only thing I see is that you can do this same process with the Cost. Since the enchantments going into the armor are the same, those materials' cost wouldn't change. However, the cost for the chain shirt and the mithril would have to get included.

So, we have 10,975gp. Take out the breastplate and we have 10,625 gp. Then add in the 1,100 from the mithril chain shirt and we get 11,725 gp.

I'd run with that cost with no change to the XP required.

 

[dvvega]

I think the armour is costed using the multiple abilities on a limited slot item methods.

It is a +2 breatplate with the equivalent of an ability bonus (perhaps 75% because it doesn't give extra spells or spell DC), +2 to a feat's inherent skill (rated at a +2 skill item?), added a permanent use-activated spell (the aura). Add in the negative for hide/conceal and you may just work out the cost.

armour: 350gp
+2: 4000gp - 3000gp due to partial restriction.
+2 CHA: 4000gp
Leader: 400gp
Aura: at least 30000 (spell level x caster level x 2000)

All these abiliteis are similar in nature (an enhancement of charisma based things) so you could rule 75% on all abilities besides base (aura).

So 30000 + 300 + 2250 + 3000 + 262.50 = 35812.5

Now since you have a big penalty with concealment etc, perhaps this is a further reduction of 75%?? Comes out to around 27000gp. Of course this is all a rough guess but the armour looks about right in price. I've probably over compensated for the values and penalties etc.