I suppose that is the gamble with EB, they fix the price before they get on the site but it could be that the work doesn't need to be done or they need to do more but either way price is fixed.
We are building the Cambridge 25, we were going to go for the 27 but decided on smaller house and bigger back yard want a bit more room for our dog to be able to run around, she is sooo active its not funny.