It completely boggles my mind how consumers and small resellers don't know how GST works. It's really frustrating when they come and say "oh but X, Y and Z are not charging GST; why should I pay GST to you?" All without realising that X, Y and Z have probably already factored in the GST paid to their suppliers in the cost price of the item, never mind the fact that I might actually be quoting a cheaper rate which then becomes similar after GST is added to the price. Or even when I'm actually charging less, period, because my prices are mostly based on B2B, not B2C.
Plenty of businesses mislead customers into believing that they are not charging GST, and the customers prefer being ignorant and believing that they're sticking it to the government when in reality they're getting screwed. Spoiler alert: most manufacturers export their goods out of state, or their turnover is high enough for them to charge GST, not to mention their own input GST on the raw materials.
Then there's also the situation where you sell items which have different rates of GST. It's hard to convince people that you're not actually cheating them out of their money. Despite the fact that you're issuing them a computer-generated tax invoice.