Looks like this will be happening every Sunday until the end of the year.
Super Sundays, Sell for $1
Edit: Fee is actually $1.10 incl. GST - Thanks scuderiarmani
The promotion runs from 00:00 (AEST) every Saturday in 2017 to 23.59 (AEST) every Sunday in 2017 (“Promotion Period”).
Items must be listed and available for purchase by 23:59 (AEST) on Sunday in order to qualify for the promotion.
Pay a maximum of $1 in Final Value Fees for any items you list and make available for purchase in a single category during the Promotion Period.
All www.ebay.com.aumembers are eligible to participate in this offer.
Store subscribers are not eligible to participate in this offer.
Sellers whose accounts do not meet eBay’s minimum performances standards are not eligible to participate in this promotion.
All it takes is for AusPost to be a little late delivering your items to not meet minimum standards.
Full T&Cs here.