With this out of stock and with Dan Andrews just making wearing a face mask mandatory from Wed July 22nd, I think $19.90 / $36.90 for 50 / 100 pcs is quite a good deal. Cannot vouch for the quality as it's my first time buying too. But, something is better than not wearing not a mask, and if you just want something cheap to avoid paying the fine.
Link to 100 pcs here.
Just ordered 100 pcs, arriving 22nd July, just in time.