Is the six transdisciplinary themes? Is? Since there are no less than six features, surely it should read "The most significant and distinctive features of the IB Primary Years Programme are the six transdiciplinary themes."
Christ Almighty, this is the sort of fee prestigious boarding schools charge in UK, schools who in return for the fee all but guarantee your son a career in the City or a Commission in one of the three services afterwards. Universities only charge £9,000 (US$14,400) per annum.