price this custom magic item for me (pathfinder 1e/d&d 3.5)

[Gallowglass]

Price this custom item for me:

"This rigid necklace is of elven craft and predates the diaspora of the elves into the desert. It is made of interlocking finely crafted leaves made of copper, silver and gold. Some of the metal has been artfully tinted a pale green. A careful inspection of the necklace reveals a "hidden asp" woven under the leaves made of mithril.

The necklace acts as a necklace of natural armor + 1 with additional powers.

While worn, the wearer has + 5 stealth and pass-without-trace while in wooded terrain only.

While worn, the wearer can squeeze through spaces 1 step smaller than normal. So a medium creature, who can normally squeeze through a small space, can now squeeze through a tiny space.

In addition, the bearer can hurl the necklace to the ground where it will turn into a viper as per a figurine of wondrous power for up to 8 hours a day. The viper can be tasked to attack, assassinate or scout. If sent to scout, when the snake returns and the necklace reworn, the wearer becomes aware of what the viper has seen. While in viper form, the character does not benefit from any of the necklace's other abilities.

[Kurald Galain]

Ok, comparing this to existing items,

Amulet of armor, 2000
Cloak of elvenkind, x1.5 for different slot, x1.5 for multiple abilities = 5625
Corset of vishkanya, x1.5 for different slot, x1.5 for multiple abilities = 6750
Figurine of wondrous power, x1.5 for multiple abilities = 5700

Total = 20000 gold. That may seem like a lot, but you are stacking four different items together in the wrong body slot.

[Maat Mons]

For purposes of calculating "multiple abilities," the natural armor bonus doesn't count. This has been true ever since the publication of Magic Item Compendium, and the glorious table on page 234.

Definitely don't apply both th x1.5 for uncustomary space limitation and the x1.5 for multiple different abilities. That works out to a total of x2.25. Which is more than the cost of a slotless item. A slotless item would clearly be better, so this is a degenerate rules interaction.

A figurine of wondrous power is a slotless item, so making it part of a slotted item should, if anything, decrease the price, not increase it. If you take the necklace off so you can hurl it to the ground and transform it into a snake, you're forfeiting all the benefits of wearing the item. So this is definitely much worse than having a necklace and a figurine. I'd take either the cost of the benefits when worn, or the cost of the figurine function (whichever is cheaper) and multiply by 0.75.