Current starting salary for the Q400 is a shade over £26K and the TR training bond £13.5K, reducing over 3 years. No repayment from you in respect of the TR bond, although if you skip town before the bond is up, Barclays will come and hunt you down as it is financed through them with a secured loan.
In respect of the NI bias, I think this is because they find BHD a difficult base to recruit for on a long term basis. The situation with CI is a little different due to the restrictions placed on giving work to those with residency rights only.