Cyber hand cost extra essence on top of arm
 

I have a cyber arm. Cost me Ess 1. I then went and added a modular wrist connector to the arm, so I could plug in different hand extensions.

I then went and brought myself a cyber hand to connect to it, but the hand cost me an extra .25 Ess.

Is this the correct calculation? I figured the arm would have already included the essence calculations, as by default I'm pretty sure a cyber arm comes with a hand.