I have a Cooler Master RS 500 I can let go for $50 if you are in AKL CBD?
I bought a couple of these recently, been fine so far.
Theres 500W model available as well but price ramps up quite a bit... so alternative would be something like https://www.mightyape.co.nz/product/500w-fsp-hexa-atx-psu/24458023?r=1462359
I thought needed a power supply, I took my PC into PBTech here in Tauranga they let me try one for my PC with the understanding that if it didn't work out to return it and would get a refund.
Which is what I did as it wasn't the power supply and replaced the cmos battery and it worked for me.