Think it's around £10k ish?
It depends how much you work (we moved back to an hourly rate rather than a fixed monthly rate earlier this year). Typically flight pay will be around £600-£700 per month on an average month though.
But we also get other Time away from Base payments etc too. An approximate for that is £4 for every hour you are away from base from report until clear at the end of a trip.
So, in addition to salary, an FO at BA on the A32N fleet working full time can expect to earn an additional £1500 per month.
After tax, average earnings for a full time FO starting out year 1 on the FPP is between £2700 and £3000 per month. This excludes the bond repayment, which is an extra £1000 per month. I'm reliably informed that with the new programme the basic salary will be higher to offset the absence of a bond (i.e. the salary scales will be inflated by approximately £12,000 per year).
The salary increases by approximately £5k - £6k per year for the first seven years on the current FPP programme until it catches up with the existing FO pay scales. And typically the scales themselves are all inflated each year by a nominal percentage to offset inflation, so essentially it's two pay rises per year.