[Anthony]

Originally Posted by evileeyore

"Only Works for 'Good' Power Investiture" isn't relevant for Can be Stolen.

"Halve the value of the limitation if the gadget will not immediately work for the thief" does not have any limitations on why you halve the value. In general, anything that prevents the item from working well for your enemies requires that half value, and "requires 'good' holy investiture" most certainly has that effect.

Originally Posted by evileeyore

Under the hood:

Spoiler:  

Rules from GURPS Basic:
Gadget [15 points] (1 point in 15 different spells, 1 point in Signature Gear, 14 points in Points For Cash ($10,000), [30]; Can Be Stolen DX or ST Quick Contest, -30%; Power Modifier: Holy†, -10%; Skill Cap 15, -10%*; Unbreakable, +0%)


* Reflavored Accessibility limitations.

Spoiler:  

You can't take PM(Holy) on abilities that already inherently have that restriction, such as divine spells. Can be stolen cannot be applied to signature gear or points for cash, as it inherently already has that limitation. A skill cap is taboo trait [0]. Thus it would be:
Gadget [15 points] (1 point in 15 different spells, Can be stolen (quick contest, not immediately usable, -15%) [13]; signature gear[1], points for cash[1])