noni- best of luck for your interview, you will be great i'm sure.

arte- what are you building?
i *think* you have to pay for all kinders, well all the ones i've enquired about charge you anyway, idk? some like to charge a lot more than others too i've noticed. it's all v confusing.

cally- i'd get one bag of balls to start with. you can always add more later.