Genghis my story is much the same as yours I think, 10 years to Chartered Engineer which is generally ignored by employers (not to mention the CAA). I don't remember what I earned when starting work as a fresh-faced graduate in 1978 but I do remember that 10 years later I was on the princely sum of £13K.
Fast forward to today and I would expect most grads to be earning somewhere round double that sum in their first proper job. I'm guessing though that despite the frequent lament that "UK needs Engineers" UK is not willing to pay them and the glut of new graduates keeps the salaries down. Little wonder then that we don't get the Engineers we want when they can go into teaching for more, or banking for twice as much (before bonuses!).
Sadly engineering is not one of life's great payers, though it remains a uniquely satisfying career. As with many trades there is money to be made by going freelance, but at the expense of job security and home life/location. Contracting is predominantly a young man's option and few are willing or able to run it through to retirement, resulting in loss of career options later in the working life. The graduate career path is pretty much the opposite, requiring financial and time commitment invested early on to reap benefits later. As discussed in other threads maintenance is largely an apprenticeship approach while the degree route is better suited to design/development. Both have their advantages but those looking at the first rung of the ladder should really be considering which is the best ladder for them.