Can people please not listen to this terrible advice that gets repeated so oft, especially in Australian IT circles somehow by young naive folks.
You really need to talk to your accountant here.
It's probably under 25% in deduction at double the median wage, little bit over @ triple, and that's *only* if you are using the device entirely for work, as in it sits in an office and nowhere else, if you are using it personally you open yourself up to all sorts of drama if and when the ATO ever decides to audit you for making a $6k AUD claim for a computing device beyond what you normally to use to do your job.