No accommodation is included in Bristol GS price - just the (excellent) course, including the two week-long brush-up courses.
So you'll need to budget for at least 4 weeks accommodation for the two courses and two sets of exams, and the 4 return trips for these, probably another £1,000 all told. Also, I think the exams cost more than the £900 you allowed.
And of course you're hoping that you'll pass everything first time. Any re-sits will pump up the bill. Also, all the flight times for licences are absolute MINIMUMS, even exceptional students seldom achieve these minimum times. The other thread gave a recommendation of factoring the costs by some 15 - 20%. This is wise, and quite realistic.