It's not quite that simple... hobbyists here are much higher on the socio economic scale than an American hobbyist for example. There are far fewer but those who are in the hobby have higher relative affluence than the average American or Australian. You'd be pretty hard pressed to find someone here making the average salary who has a saltwater tank. I know this doesn't prove anything necessarily but they actually do sell Australian Scolys for absurd prices sometimes and they always are bought. If you think 2,000 is scary, I've seen Scolys for 18,000 and people buy them. It's almost only those with high economic status who are in the hobby here. People working at 7-11 wouldn't even consider it for a second.Here is the big BUT....so an acantho is around 2000 baht what equals 57$. The average Thai montly income is 39000 baht and that's 1130$. That's 13560 a year. The average Us Income is 53490, so 4 times more. Same in Australia. Here it is 69888 au$ a year. Now those coral prices fall into order a bit more too. I love the acantho too but the prices scare me...
I worked out the percentage cost of an Acantho in comparison to the figures you gave for Thailand and the US and it still is almost twice what it is here. Also take into account the inflation in America ATM. As for Australia, I don't know enough about their current economy to say much.