Willingness to relocate (or lack thereof) is what allows Wizz to run their show however they please across the Eastern European bases where they are often the only carrier who has a crew base in the city/country (or one of two or maximum three carriers). Local pilots aren't exactly spoiled for choice if they want to work out of their home city - and many spend a couple of years in different bases, waiting for their turn to be relocated to their home town. If they're happy to accept whatever Wizz have to offer as long as they're at home every night - well, everyone has their priorities.
The more interesting case studies will be the Western European bases. As Sick rightly mentioned, the London area is an example of a place where multiple employment opportunities are available in normal times. That's where things will get interesting whenever the market picks up. Either the conditions in Western Europe will be a long way better than in Eastern Europe - or there will be a prevailing presence of inexperienced guys ready to take everything to get a foot in the door and high staff turnover in Western Europe.