I'm sure you know of Paul Clitheroe from Australia's Money Magazine. One phrase he often says is, "If it's too good to be true, then it probably is."
You will have to pay tax in Taiwan, and if you don't, then the ATO will deduct the tax for themselves. It's either you pay the tax to the Taiwanese government, or pay it to the Australian government.
There are 2 tax categories in Taiwan.
* Category A : 0 ~ 183 days - You must pay 20% tax on your income. No deductions can be claimed.
* Category B : 184 days or more - You will be taxed according to the following progressive scale.
See
http://www.aacircle.com.au/teach-in-taiwan.htm for full information on the tax system.