I think this may be part of Aldi's 7 day deals. Available at Aldi stores in the northern suburbs of Melbourne (Northland SC, Summerhill Village). Had some yesterday, which were unexpectedly juicy, sweet and had small seeds, so went back for more today! Grown in Australia. Not sure if available at all Aldi's but definitely worth having a look around.
Edit: pricing may vary from store to store
Work at Aldi, they're normally 5.99, not sure why you were charged 3.99, probably just that store selling it at that price