Wired 3 is a really shaky purchase, and more than 12 anyways. Did you mean Wired 2?
Some good examples (and keep in mind this is already a problem, it's more that lowering availability further makes it a bigger problem):
It makes purchasing stuff like glasses/goggles/contacts a major pain in the neck - you probably want to start with a cheap pair that just Smartlink you, then take your first paycheck and buy real ones - they aren't expensive, but they have high availability.
Cyberspurs, Cyberarm Gyromounts, Monofilament Whips, etc are all items that are pretty cheap and that a character might not function properly without (ie, a Monofilament Whip user can't start with one - but they can buy one easily enough after gameplay starts).
Synthacardium is a perfect example, actually. It's not very expensive, so you really don't want to start with any synthacardium - if you want it, you should wait to buy rating 3 rather than start with rating 2 and have to trash it, wasting money. Ditto on Tailored Pheremones - it's something every face will want, but they won't want at 2 - so they can either wait to buy it, or waste 30000Y. Cerebral Boosters have a similar issue - nobody is going to want Cerebral Boosters 1 that they then need to throw out a few missions later. Also, that doesn't really do much to keep Charisma skills in check.
If you want to keep Charisma skills in check, I suggest (1) ban Empathy Software and Emotitoys (2) Use the dice pool cap = 2x(unaugmented attribute + unaugmented skill) rule, which is a good one in general.
If you want to stop people from starting with 3 IPs, I would suggest just spot-banning the handful of ways to do it. What about adepts, by the way? Also, keep in mind that there's various ways besides sustaining foci to let magicians get a 3rd IP.