XYZ is most often blood glucose measurement strips, especially for those
who don't live near discount pharmacies and must pay cash for their
supplies. Mail order prices are not always lower than local prices.
Remember that there is an advantage to going to a single pharmacist for
all your drugs, if that pharmacist is knowledgeable about interactions
and tracks all the drugs you use. Adjustments will be slower if you mail
order. Never mail order unless you are certain about what you need.

That said, here are two starting points.

_Diabetes Forecast_ has a long advertising section, part of which is for
suppliers. Nowadays most list their web addresses in the ads. In
addition, each issue of _Diabetes Forecast_ contains a column
summarizing recommendations for ordering health supplies by mail.

Jeff Hitchcock's Children with Diabetes web site has links to quite a
list on suppliers with information online at
http://www.childrenwithdiabetes.com/d_06_900.htm.

I have removed the list formerly kept here because it was years out of
date and done better elsewhere. This leaves no information for those
outside the US, as the above links are mostly focused on US sources. In
the past, this has been much more of an issue in the US. However, web
search engines might be a great help -- googling "diabetes supplies
Australia", without the quotes, yields nearly a million hits. Just be
careful to evaluate what you find.