I've learn from InWroclaw's thread that a renting of a flat in Poland and in the UK is about the same cost. I've already know that food is usually cheaper in the UK as well.
A good size flat is not much more in many parts of the UK, sure. A shoebox flat is of course cheaper in Wroclaw, obviously.
All flats are much more expensive in Wrocław in real terms if based on local wages as wages in Wroclaw are much lower and yet rents are not.
Fruit such as apples and oranges are more expensive in the UK, and macaron/pasta usually is too. There are food items that are more expensive in the UK, but again not in relation to wages and real terms based on salaries.
In my experience, a typical grocery shop in Poland is not that much cheaper than a Briton pays. Yet a Pole's wages are much lower and their rents are not cheap and if they rent a decent-sized flat then their rent is nearly the same as in some UK cities. Of course, Britons have to pay council tax (a local tax for services such as garbage collection, street lights, libraries, schools, emergency services, street cleaning, and keeping a lot of bureacrats in easy and well paid jobs) each year of around a thousand pounds, sometimes more and as far as I know that is included in monthly service charges for Polish flats or is perhaps not chargeable at all in some cities (although that will perhaps change!).