But age isn't related to pay, postage - you can work all your life in a less well paid job, be very good at it, but if there is no way to progress upwards, then the job is paid what the job is worth. It's the job which attracts the salary, not the calibre of the person who's in it.
I know people who are worth a great deal more who have worked in well paid places, but who've lost their jobs in cutbacks and are now earning less than £20K in their fifties. Holding down any job these days is an achievement, irrespective of how much it pays.