Right. Bad phrasing. I meant X/3. I.e. after subtracting the essentials, I'd be able to afford 1/3 of good and services equivalent to what I could afford in my current location on previous salary.
The salary I referenced is high for the region in general (and I had it on a remote contract with an US company, though in hindsight, it was under market rate), but not necessarily for our industry, for the position I would be otherwise aiming for locally.
From my calculations, London works out quite well if you're single and willing to sacrifice heavily on the living space. It also works out a-OKish for two-income families with children at kindergarten age. Not so well with a toddler; I was shocked to discover that daycare costs more than rent on a two-bedroom flat west-side.
My friends in Warsaw are pulling anywhere in the range of $55-65k per annum before taxes - that's at corona rates, which knocked close to 8% off our currency's value.