From my experience, this is what makes Berlin less attractive than people think (at the financial level):
- low engineer / developer salaries compared to other German cities. - rent prices are growing a LOT faster than salaries, my last appartment outside of the city center (the "Ring") cost almost 900€ a month, plus electricity. - public transportation is not that good (especially in winter) and quite expensive relative to the avg. salary (about 80€ if you live in the AB zones, 100€ for ABC). - high taxes, though this is a common problem in Germany. - food is cheap, but not cheaper than in other German cities with better avg. salaries. - if you own a car, prepare for extremely high insurance and taxes
Obviously, Berlin has its own perks, besides the known ones like night-life and openness of the people, it has a really huge demand for engineers and a vibrant startup scene.
Anecdotally, salaries are lower and rent higher as compared with both NY and San Francisco. Taxes are obviously higher as well.
In the absence of the COL index for the UK we can use the "London living wage" - supposedly a baseline for a minimum acceptable standard of living[1] which translates to £18k (a little under $30k). The tax paid on the amount earned in excess of this living wage is around £7k (<$11k) That would leave around $19k of savings or "discretionary spending", actually slightly better than NYC and Portland despite the low salary, but based on what is almost certainly a much less generous view of essential costs of living.
[1]Since it assumes dependents it's quite a generous minimum standard; indeed excluding tax payments from the equation I've never spent more than it whilst living in London on substantially higher income. But it's also almost certainly less generous than the COL assumptions for the US cities.
https://s2.yimg.com/bt/api/res/1.2/626WvTKmFK2FRBFpBg9rNg--/...
This is for buyers but the rental market price rates have gone up in pretty much the same way.