50x Disposable Masks (3ply) $5.99 + Delivery ($0 with Prime/ $39 Spend) @ HomeWork& Play Amazon AU

Came across these. Seems like a good deal.

They are shrink wrapped in packs of 10 which is nice rather than all loose packed in the box.

From a comment below:

Image on product shows the standard is: T/CTCA 7-2019

According to TGA’s guidance(tga.gov.au):

Due to the lack of resistance to fluid penetration, masks designed to certain standards or subclasses of some standards (listed below), may not be suitable for use in medical or surgical settings.
T/CTCA 7-2019
These masks may still be appropriate for use in non-medical/healthcare settings to assist in reducing airborne disease transmission, along with social distancing measures.

Enable registration in settings - general