I'm lookin' into getting a focus chip too and I was wondering if anyone knew about what skill level you could economically move up from the minor to the medium, entropedia didn't really help me there :/
But take note!
One thing I learned about tossing focus into the mix is that you keep trying to sweat a creature and sometimes accumulate some naaaasty armor decay :/ and a few times I oopsed and died, great way to lose time, decay, and charges
