Even if it is merely one effect, but you think the item should have two spells associated to the desired effect, are the costs added together as if you would make two different items with different effects?
I'd normally price the item by the more expensive of the spell prerequisites unless a similar item already exists.
Page 549, CRB.
If an item has two effects that are similar, then you pay full price for the most expensive, 3/4 price for the next more expensive and 1/2 price for the rest.
No, if it only has one effect, then that is all you pay for. Doesn't matter how many spells you chuck in it to get that effect.
There is a section in reducing cost due to restrictions, if that's what you mean. What exactly is this item?
There is no such thing as an arm slot. I assume you mean the hand slot, and the wrist slot?
I suggest you make it one or the other. It's effectively a feat equivelant item (Lunge feat does this), so it shouldn't really cost too much.
Some materials to 3.5 (single PF item as well) misnamed wrists slot as arms slot (because of, you know, armlets, and wearing bracers on arms).
Dabbler, do you know where the feat equivelent list is referenced in any of the books? I'm looking, but there have been times that no matter how hard I look, I just can't find what I'm looking for. And as far as making it one or the other, maybe. I'll have to give it some thought.
Nearest equivelant is something like the Mighty Cleaving weapon property, so I would make this item according to the weapon rules, as a +1 equivalence. So about 2,000gp, less if you give it limited uses.