2 months at a time is OK with me if/when Thailand sorts itself out for a 2-month visa-free on arrival and one Bt1900 30-day extension, which will be convenient for 99% of Thai Tourists. 3 months for Bt1900 for a 90-day holiday is OK by me and many others. It's only the long-term residents that now have something to worry about and may have to pay income tax in Thailand...maybe???
It is unlikely that Australians who get the Australian Aged Pension (AAP) and some super are likely to be free of Thai income tax. The AAP in Australia is not taxed if you are under the ATO threshold and super now has already been deducted of 15% of the profits. Any dividends are then or now tax-free in Australia and most likely in Thailand.
...Although I have never been asked if I have an exit ticket, the rules say you could be requested to have one...it's up to you (that's a Thai standard answer).
The world cannot survive if people do not pay some taxes. I would prefer to not pay any tax but I know that is not practical in a modern world. I can easily afford Bt1900 and just grouch daily about visa prices in Thailand, then grin and put up with it. It's not a lot. It could be better, 3 months at a time... maybe.
...I thought the reason for going to live in Thailand is it costs so much less to live, it is for me, and I'm happy with that. The same room in Perth costs $300 a night, Thailand about $300 a month.
To get the best advice we need to know what type of visa you have....i.e tourist visa, retirement visa, business visa etc. etc. I think there are many visas available.
You get them a 90-day tourist visa in your own country at a Thai Consulate. They are for 60 days and you can extend them for another 30 days in Thailand. I've had 12 of them. That is what Thais call 90-day tourist visas but this is Thailand. TIT. You can use them up to 90 days after issue, you need to have a bit of money for your trip in the bank and Bt1900 if and when you extend them.