Looks like this phone is getting remarkably popular with Optus Netflix deal.
The best price for paid unlock code I looked up was $2 which seems… not so reasonable for $15 phone.
So here is the free version.
1 – Find ZTE unlock code generator somewhere in the web.
2 – Switch ON your Phone WITHOUT SIM Card,
3 – Then dial : *983*8284#
4 – Enter Unlock/ NCK /NP code generated from above.
5 – Your phone will shut down automatically
6 – Put non-Optus SIM and try if it works
As usual, at your own risk. I don’t run the calculator site so don’t know how it works internally.
Hence I can’t give any guarantee whether it will work with your phone or not.