Stock levels: https://nrby.in/bunnings/0356854
Price history: https://pricehipster.com/product/4PIqR5M_ouvoXv_rvnKwag~HJ1K…
Normal price ($60-$100) more expensive because they can tolerate going through nails. If you don't need that capability then $25-$40 seems to be the usual going rate for a set like this of decent quality from the likes of Sutton, Milwaukee, Irwin, DeWalt.
Finally, a set of auger bits strong enough to drill through the depths of Sanctuary