If it has electro pencil markings it is probably a Russianicon Capture. Should also have an X on the receiver, might have a purplish colored stock. If that is what it is, I'd grade it on overall condition. Like I said in an earlier post, they have not been available for sale where I've seen them so I don't know the current going rate. $600 may not be bad if condition is good although I think it's pushing it.