When I was looking for an appartment, here the figures I finded
In TPE, between 25.000 - 35.000 NT$ for an house on western standard, add 10.000 if you want to be in Tienmou area (near the international schools), remove 10.000 NT$, if you leave outside TPE (near CKS for ie).
But of course, it all depends on what you find acceptable and what size you want like in every other city in the world.