Came across this when walking around at Bunnings. $4 is pretty darn cheap. Also have a $10 one as well if you want to splurge. The $4 one is normaly about $10 and the $10 one about $25.
Handy just to test the voltage of your batteries if nothing else!
Found them on the website, links below:
Cobra Hobbyist Multimeter - $4
https://www.bunnings.com.au/cobra-hobbyist-multimeter_p01068…
Cobra Hobbyist Plus Multimeter - $10
https://www.bunnings.com.au/cobra-hobbyist-plus-multimeter_p…
They include a 9V battery which is probably worth the entire $4 just in itself.
I use it for work
Last 6 months
Good enough