I was looking to buy the Xiaomi ultrasonic toothbrush but then saw this Woolies for $30 and decided to give it a go. Entry level but according to most reviews works just as good as the high end ones. Amazon (lowest I could find) has it at $39.
The refill brush heads are 1/2 price too.
Advice: the online catalogue has the older 2018 version (same model number and everything but green box) but you might be able to find the newer 2019 version (black box) in the isle. The difference seems to be the battery lifetime (14 vs 10 days as advertised on the box).
Oh I wish they had half price Sonicare replacement brush heads!