The cost of a skill is New Rating*2, for each rating you want. So if you don't have Throwing Weapons at all, rating 1 will cost 2 karma, rating 2 will cost 4 karma, and so on. With 32 karma, you could get up to Throwing Weapons 5 for 30 karma, or Throwing Weapons 4 (Aerodynamic) for a specialty that applies to shuriken for 27 karma.
a Shuriken has an Accuracy equal to Physical Limit, Damage equal to Str+1, and AP -1. The ranges are 0-STR Short, STR*2 Medium, STR*5 Long, and STR*7 Extreme.
With an Ork Street Sam with 8 Strength, that's 9P -1 AP, which is better than most heavy pistols, and your accuracy probably is too, since you'll have a hell of a Physical Limit. The range is also comparable to a Heavy Pistol, with 0-8 short, 16 medium, 40 long and 56 extreme.
Not only that, but you can always collect your shuriken from your enemy's body after throwing them, so you don't even really have to worry about ammo.
So yes, for your build, it sounds pretty worth the cost.
