Prices of GPU are around 110% of MSRP. $320 USD == 422.368 AUD, so you're not getting a bad deal there.
for the price I would change 2 thing:
wifi card. REALLY ? if you use that thing wifi speeds will be embarrassing slow. you need
1. up and away from case.
2. something with antena big enough for desktop (you really cannot use 10x faster cable in desktop ? ) Panda Wireless PAU06
consider another SSD:
1. 120 GB are ALWAYS slower than 256 and bigger.
2. if you use m.2 why not utilize ALL possible speed and stay around sata ?
https://www.amazon.com/XPG-SX8200-480GB-Gen3x4-ASX8200NP-480GT-C/dp/B07BLNFSQN?tag=bom_tomshardware-20&ascsubtag=THUS86271527481838367-thaus%3Aen_US_18_Review_3891&SubscriptionId=AKIAJLYKPRLXUSF4GDIQ&linkCode=xm2&camp=2025&creative=165953&th=1
that thing is 6x as fast, twice the size for twice the cash. your choice.