Magical Glass Eye

[Dovius]

So I came up with what I assume is probably an already used idea that I can't find anything about on my own, and my DM is somewhat uncertain what to do with it, so I'm calling in the help of people with much more gaming experience than me to take a look at it.

The basic idea is that it's just a normal glass eye, yet enchanted to function like a normal eye. No low-light or darkvision, no arcane sight, just the capabilities of a normal Human eye.

Aside from the ability to take it out of it's socket and having it still function.

Which is a rather large boon to my Rogue for various scouting/thieving/sneak-stabbing purposes outside of combat (Take it out and hold it around a corner, drop it in a semi-hidden location to use it in a manner akin to a camera, that kind of stuff), due to probably having him on his face vomitting from headaches and motion sickness if he tries any sort of combat or coordinated ability due to Human brains generally not being wired to handle 2 viewpoints at once.

The question we're dealing with at this point is somewhat two-fold:

1) How would this be balanced with normal vision in regards to penalties and bonusses? I'd personally say that it doesn't give any bonusses at all and gives some rather harsh penalties if the aforementioned combat comes up, but the mechanics of the thing in general kind of make both of us scratch our heads in regards to balancing.

2) What would the hypothetical price of it be, and what would be needed in regards to spellcrafting and enchanting to make the bloody thing?

Apologies in advance for basically barging in with an idea and asking people to make up all of the rule-related stuff, but if anyone could find the time to help me with part of this, you'd have my thanks.

[Serafina]

Well, just replacing a lost limb (or sensory organ) should not have any actual cost attached - all magical items i can think off do come with additional effects that justify their price.

Basically, you are getting a limited divination effect.
If we take Clairvoyance (provides sight from a magical sensor within long range) as an example, it has much longer range with a limited (1 min/CL) duration.

The easiest way to do this would be to just make it a use-activated item of Clairvoyance that takes up the eyes item slot, with the "need to cut out an eye" being balanced off by replacing the function of that same eye. That would cost 3(spell level)x5(minimum CL)x2(due to duration)x2000=60K gold pieces.
However, the object doesn't actually let you create the magical sensor anywhere within its range, you have to place the physical object there - so thats not a fair price.

So lets slash down the effects to a 2nd-level spell in exchange for medium range, and require placing a physical sensor in exchange for longer duration (hours/level). That gives us a cost of 2x3x2000=10K gp.
You now have a glass eye that replaces a lost eye, and which you can see through even if it is disconnected from your body (as long as its within medium range).

[Lycoris]

As an alternative, there are some variant rules available on the PFSRD for Prosphetics (http://www.d20pfsrd.com/gamemastering/other-rules/variant-rules-3rd-party/4-winds-fantasy-gaming/The-Loss-of-a-Body-Part/Prosthetics) that might be worth looking over with your GM when working this out. Particularly, the section on Magical Prosthetics, which largely seem to be made using Craft Wondrous Item, Animate Objects, and whatever spell/spells you want to add to the prosthetic.

By and large, Serafina has already pointed out much of the monetary costs and spell requirements that would go into making such an item.