To put another, more positive spin on things...
I took a 40% pay cut to move to BA. Frankly, I honestly don't miss the money. You can't put a price on quality of life and a decent career.
Anyone who thinks you can't have a good life living on £4k net a month plus, even with kids and living around London, needs a very serious reality check. The starting salary of £4k a month net puts you easily inside the top 10% of UK earners.