As the culmination of your early study of the fundamental forces of the galaxy, you have created a spell cache that allows you to store and access spells. Your spell cache could be a device like a handheld computer or technological implant: an item such as a ring or staff; or a symbol such as a brand, tattoo or other permanent modification to your body.
I'm having trouble understanding if the Spell cache is free or not. Since it seems to behave like the wizard's arcane bond I am under the impression that its also free. Lets say that I wanted to have a prosthetic arm as my cache (suboptimal, I know but it seems appropriate to my character idea.) do I have to subtract its value from my starting wealth?
Oh. Great, they aren't in Starfinder because they lack that language and giving away a free item without any limits would be horribly unbalanced. From an optimization standpoint I recommend a vostless tattoo rather than an item you might have to hold to use and that can be destroyed, at least until you can afford a Holographic Harrow Deck.