I live in a nice area at the moment and have a good, secure, job. Progression is pretty guaranteed if you want it and I could easily be on £60k-90k in a few years (although probably in a job that's a bit boring and often high pressure). The area is a desirable town and is fairly expensive from a housing point of view.
I have an opportunity to move to the south east, near the seaside, to a job which would be interesting and challenging but doesn't have the same earning potential in the medium term. In a few years I'd be on £40k but in 15 or so years I could get a day rate of £500+. There is absolutely no flexible working with this job and of course housing is even more expensive than it is in my current town.
I'd like to have kids in a couple of years so that is a whole world of expense that as a non-parent I am vaguely aware of. I'm single so I could potentially be becoming a parent alone.
WIBU to take a lower salary career route to move to a more expensive area?