Australia seems to pay roughly on a par with the US, or did when I lived there. But most of the UK is dreadful - software folks are paid poorly and treated like drones.
Unfortunately there are enough people that will take the bad salary, have mediocre performance and deliver mediocre software slowly, that a lot of British companies now expect to pay peanuts and get monkeys.
I've found the only way to replicate the money you can get elsewhere is to be a contractor. You can make about double your quoted figure outside London (my experience in the Hampshire/Wiltshire/Dorset region), or triple or more if you land something bank related in London. No idea what might be available in Edinburgh.
That will probably lead to an exodus of the experienced developers from the UK. This will not only have a negative effect on UK software houses it will also exacerbate the existing problems with UK government IT projects, which have already have a multibillion-pound problem with failure to deliver and cost overruns as it is.
Meanwhile, Russian oligarchs are still paying peanuts for their empty central London mansions and big companies are barely paying any corporation taxes.
The effect so far of Brexit is to stop the flood of newcomers, not making establishing people leave. It's good as a developer, less competitors for the same amount of jobs.
The effect is compounded because a) good techies really like to work with other good techies and b) losing most of the good ones also means losing all of the people who can recognize other good techies and hire competently and c) there's a scarcity of mentors too, impeding the ability of junior techies to develop.
The UK is still a tech center in spite of Brexit. For now.
I've worked in markets before where there's a scarcity of high end talent because it all got sucked away elsewhere and software-wise, these environments produced mediocre crap.
They stay in the same area. They are not mobile to move themselves and their family across the border periodically.
I don't doubt that there will always be some that won't or can't cross a border though.
Contracting might be a good thing for a tech guy with a specific skill but a lot of people like me like to have something standard and be more secure in a way that they won’t need to search for another gig in 3 months. I guess the more contracting you do the more reliable you become and you constantly close down gigs knowing your intake for a year before signing any contracts, but I’d say it’s still a bit hard.
From what I’ve seen if you are a developer going to Manchester or Birmingham or something like that and getting a gig might be the best thing you can do, since the cost of living goes heavily down and the salary drop is not that massive unless you were working on finance tech which tends to pay higher.
It helps I enjoy interviewing and seem quite good at it.
--edit-- it also helps I don't have a family to support, so consistency of income is less of a concern for me.
Also, you don't need private insurance when you're 67, that's what Medicare is for.