10 years ago Barcelona was much cheaper than London on all fronts, especially property, taxis, food, eating out, tobacco, & booze. Given the exchange rate at the time, living in Barcelona felt like it cost about half as much as London.
Today, Barcelona is as expensive as London for lots of things except rents, taxi, & public transport. The price differential has shrivelled up. Incomes, on the other hand, have not. So costs have converged, but incomes have not. The good residents of Barcelona are getting a lot less for a lot more.
Mind you, when I go to places like Extremadura and Galicia, it really strikes me as cheap.