It's been a while since I read the manual so there's a possibility I am mistaken in my recollection, but I am pretty sure the hefty excess bit is accurate and it would seem more likely that the instructor would pay any excess rather than the student. Having said that it's also possible it could be waived/reduced for a training flight, I honestly can't be 100% certain as it was that long ago and was a bit of information that didn't apply to me anyway.