I was due to take the ISEB intermediate, so bought this to help with the study. It follows the syllabus very closely to which it is a useful companion.
That said, it is a very slim volume for the price, especially when you take into account that there is quite a lot of repetition from the foundation. Given that (I would imagine) a lot of people who take the foundation are likely to want to progress to the intermediate, then it would perhaps make more sense to combine the two publications with a more reasonable price tag.