In 2012 I was trying to buy Bitcoin from New Zealand. At the time bitcoin was the latest craze over youtube and from memory worth around $50 USD.
I remember attempting to do buy it, but it was near impossible with websites linking to other websites and for the life of me could not find anywhere to buy it.
What a pity, if it was straight forward, I would have purchased, as you did. Now I have around 800 xrp, but don't expect them to go over $2 realistically. I think SALT and EOS coin are the next big thing.
So where does one buy Sia coin?