Just checked with a friend of mine.
Primary residence located west area : around S$1500, their place about 1300 sq ft.
2nd property : around 5k plus ( I think place about 1500 sq ft)
3rd property : around 10k plus (I believe it's around 2000sq ft and above)
Been to his place on the west coast, as for the other 2 it's what he told me.
All in about 16k or more in property tax.