Where can I buy extra shutter release cables for Cactus V5 triggers?

[KrisHunt]

Where can you get extra 3.5mm plug cables for Cactus V5 triggers (besides directly from Gadget Infinity — $7 for one seems a little steep)? I don't even know what to search for. They call it a "shutter release cable" in the manual, but searching for "shutter release cable" only yields wired remotes in the search results. No luck searching for the model number, either.