Propensity, welcome to the Mosa.
One word: SEARCH You wil find details about rent, food expenses, entertainment. Cost of living has been discussed ad nauseum, and the general conclusion is that it depends on YOU. You cannot live high on the hog but 25 thousand is more than many Taiwanese make in a month, so you should be fine as long as you control your impulses and keep your head on your shoulders. In the good old days we received less and survived…
The NHI -national helath insurance- is mandatory, four months after you received your ARC. It is quite comprehensive -dentistry, hospital tests, stays-, and for normal conditions is just fine, no extra insurance necessary, EXCEPT for those first four months -when usually everyone comes down with something, Murphy’s Law you know. Example of use: let’s say I get a cold. I go to the doc. If I have NHI card, I pay only 150 nts, medicines included. If I don’t , that’ll be 600 nts.
As a warning, though, I’d say: Do not risk, though, to lie about any current chronic condition, if you have it, as you do not know what may happen here. Example: epilepsy, heart conditions, asthma, etc. What would happen, if, let’s say, SARS comes back again? It would be your responsibility then, beyond NHI. Also, as said before, Hepatitis A/B vaccinations are suggested.