Throwing Stars to me seem like somthing small but fun to add into the game. I would guess that the damage would have to be like about 10HP, but if you can throw 3 - 4 per second you can do quite a bit of damage.
They could be bought like for one credit, but then when you by ammo for them you can get like 20 stars for half or one credit. Just an idea to bring some more fun stuff to the server.