The City is a bad idea. Don't do a job you hate to fund a job you love - you just won't have the time to fly either. Far better to find an alternate career you love to fund a passion, as it will show through in airline interviews if you have done something worthwhile with you life pre-flying.
Besides, the City does not pay the mega-bucks it did in the past - it won't fund your flying career if you have to fund the socialising required of a successful City employee if you want to be the one paid the big bonuses. It is circular.
Back to the OP's question:
Are you on the UAS or at university at the moment? Meaningful-paying alternate careers could require a degree, though not impossible without.
To the original question - ppjn.com has some guide to payscales