I could try and find the additional costs versus the "extras" that Oxford offer over Cabair.
Oxford is by definition, more expensive full-stop.
I think that Cabair is approximately £55K whereas Oxford is £63K these days.
Not sure where you get your 2K difference.
However, here's a bit of small from Cabair regarding examinations....
JAA Examination and Flight Test, Licence Issue Fees.
These are currently £840 for the first attempt at 14 Theory examinations (£60 per subject),
£691 for the final Instrument Rating Skill Test and
£315 for CPL/IR Licence and Class Rating issue. There is no VAT on JAA charges.
That's where your 2K is anyway!
Oxford include the above costs as part of the total course fees.