Pleased to hear that boro girl, I thought you would find something.
The price seems about right, my sister paid only about £100 less for one week at the BHC mid-August 2005, but her group was 2 adults & 2 kids and she was self catering. She also had to book early being restricted to that particular week for her work leave and girls' school holidays (1 daughter uni & 2 secondary)
My old school friend did manage to get a very good deal when she booked just a week previous for the last week July 2005 through lastminute.com - herself, husband and their 6 year old at the 4* Halland Hotel £852 - apparently Butlins for the same week would have cost them £100 more!
Anyway, I am sure you will enjoy yourselves, the bus station is only a few minutes walk from the BHC, you can explore most of the island very cheaply by bus. There are quite a few bars in the area for the evenings, last year there was a nightly entertainment programme at the BHC and a kids club, I am sure you will find more than enough to fill your week.