Rhonda,
The advice about buying winter clothes at the destination is spot
on. Don't waste your money attempting to buy them in
Singapore.
As long as the temps remain above freezing, you should be able to
make do with a sweater. Also bear in mind that you'll probably
bundle up less as you get used to winters there.
Hopefully, winters in Melbourne don't look like this:

That's an image taken during the infamous Winter of '97/'98 here in
MN. It wasn't particularly cold that winter, but, boy, did it snow!
