... is ridiculously cheap. Seriously, four cyberlimbs with Armor(2), and you have better than an armored jacket with the family jewels swingin' in the wind, and it stacks with literally everything.
My personal ruling will be:
Cost:
... Obvious Armor (Obvious limbs only): Rating * 500 nuyen, Rating * [2] Capacity
... Concealed Armor (All types): Rating * 1,000 nuyen, Rating * [4] Capacity
Availability:
... Obvious Armor (Obvious limbs only): Rating * 4R
... Concealed Armor (All types): Rating * 6R
Rating Limits:
... Hand/Foot: not available
... Half limb: 1 point (each limb)
... Full limb: 2 points (each limb)
... Torso: 3 points
... Skull: 2 points
It's a little more sane - just a touch more expensive. (And note, slightly more readily available if you get the "obvious armor" version; the stock version is Rating * 5R. The downside ofthat is, well, "obvious armor on an obvious cyberlimb" ... social consequneces about.)