What are sizeable engineering teams in Google Sydney? Are there engineering teams elsewhere in Australia? How much is the differential between UK TC and Australia TC? Do they try to match somewhat with your current TC - with a market rate multiplier, or do you need a competing offer from Australia for them to entertain a higher offer? TC - 540K
The same in the UK, FAANG’s are paying 60 000£ for Senior Dev, what is enough to pay for a flat 2000£, food and small expenses. You are just living from paycheck to paycheck.
You're not going to better that TC or come close. Generally speaking Australia has very few "tech companies" pursuing top talent, Google practically had the country to itself for decade plus. The pay is low relative to the equivalent level overseas, especially considering currency, and the housing is something to behold.