a lot! shipping even minimal stuff is expensive, then visas etc unless you are sponsored easily runs into thousands of pounds. not ure how up to date this is but costs of a couple of thousand per visa
Visa Costs
The cost of visas varies widely and is dependant on what type of visa you go for. For example a 5-year business visa cost approximately £2,000 whilst a 4-year last remaining family member visa cost over £2,500. Check the Australian Immigration Webpage for more details.
Other Visa Costs
Other visa costs such as medicals and police reports can be around £250 per person
Assurance of Support
Some visas require an Assurance of Support from an Australian resident and is around $5,000 for a single person or $7,000 for a couple. Check the details of the visa to see if this is required or contact the Australian Immigration Department
Australian gov website says $2370 for first applicant, $1185 additional applicants over 18 and $595 for applicants under 18, so for my family (2 parents, ds1 17, ds2 13, and dd 8) that would be £2882 in visa application fees alone.
shipping easily up to £5k, plus flights of around 6-700 per person, plus deposits on rentals or solicitors fees on purchasing, easily £20k to move. Unless you have a property with plenty of equity in this country im not sure how many people can afford it.
I've visited Australia several times and have family in Melbourne and Perth and my friends in Perth and Sydney, but its not the idyll that many people expect, especially if you still have to work. You still have the daily grind, commute, school run. food shopping (not as many home delivery services, I believe), washing, cleaning, but in sunshine, sometimes unbearable heat. I loved visiting and can't wait to go back again but better the devil you know for me.