Played Futures in Central and S. America had the same, faint-at-the-price 'sticker shock'. Luckily, the perks of being somewhat decent players, we were generally given balls, but random hits here and there, playing some social stuff, etc., I would bring balls. That's a BIG gesture, there, when it was $10 a can!
Ouch. One can would buy you 2 or 3 nice meals.
I was told it was Duties placed on such foreign and 'luxury' items. Anything 'local' was quite inexpensive. Anything imported got hammered, but since there's very little income tax collected, revenues are paid by VATS, as most make very little money.
However, I would have thought that Australia would be producing their own balls?
I would be in favor of $5/can+ balls, here (Federal Sales Tax), if it meant getting rid of the IRS and the INSANE tax code, but the bloated-and-growing-ever-larger Federal gubmint' would NEVER do anything to lay off 175,000 ''Revenooers".