Grand charm

I have a grand charm 15 ar and 12 fhr was wondering the value

15 ar? as in 15 Attack Rating on a Grand Charm? if so, i am afraid your GC is worthless. 12 FHR is not a roll, they all have that if they have FHR. the AR is a roll between 6-132. People are specifically looking for 130+, anything less is not worth a trade unless it has another good suffix. this is either junk, or you use it yourself if you need the FHR to hit a certain break point; such as 86% FHR on a Sorceress.

Is AR all res? If so this might be valuable