Danon,
As a stand alone domain I wouldn't pay the registration fee for it but if there's existing interest in the term "you will save" or you want to build it into something then the phrase itself is quite memorable.
For most domains I don't buy the .net.au if I have the .com.au but this isn't always the case. For $20 a year, holding the .net.au is a good way of stopping competitors using it and can increase the value of the .com.au in a sale situation.
I've made offers on plenty of .com.au then elected to go with a .net.au. If the .net.au wasn't available I would have coughed up the cash for the .com.au.
It all depends on what your using it for.