That's certainly important, the .au had slipped my attention, surfing the side on my phone. It doesn't explain the difference in price between these seemingly very similar subwoofers but it adds to the appeal.
70 W RMS is not an awful lot of power when it comes to bass reproduction. When set up as intended (close to the front wall, ideally close to a room corner) and tamed by RoomFit it could still work well at limited volume levels.
In my experience even a cheap sub can really enhance the enjoyment, especially with small speakers.
