Ok, had a player ask me about Cyberarm, Decks, and Crainial Decks. I clearly remember there being a (Cost)*4 for adding Cyberdecks into cyberarms, but I fail to find it. Am I just remembering Cybertechnology?

p36 of Man and machine.
5 ECU for a custom deck, 4 ECU for a stock deck.

I'm looking for something that says Cyberterms in Cyberarms cost 4* as much /nuyen/.

Yup, looks like you're thinking Cybertechnology. Pg. 35, Cyberarm Cyberdeck says, in part, "For standard decks, multiply the price of the selected deck by 4, increase the Availability target number by 25 percent (round up), and double the Base Time for acquiring it."

Glancing through M&M, it looks like a deck just takes up ECUs (4 for a Stock deck, 5 for a Custom deck), changes the concealability modifier (-3 if stock, -4 if custom) and can only be controlled cybernetically if connected to a DNI. Looks like cost doesn't change. I might be missing something though.

Nah Eidolon, you got it right and you beat me to the punch. *shakes fist* That's what I get for following up the Shadowtech reference, which seems to be a red herring btw.

EDIT- IMO the Shadowtech build your own versions are much better.

Agreeing. Customised is good according to VR1,VR2 & Matrix.