Scholastic's goal and ethos (from its public credo) are uniquely positive and fit me personally (general respect and good positive attitudes not backstabbing for self-promotion) as well as professionally (not burning out, not abusing unclocked overtime, protecting long-term careers).
I was honest and said I am not familiar with the TTM . After they explained it to me I told them of a story how a prospective client was not ready for personal training. I didn't press the issue with him, gave him a packet of information on my services and said, "When your ready for training or you have any questions, feel free to come find me." Three months later he came back unexpectedly and bough a bunch or services and products from me. I met him in the Pre-contemplation phase and my information and parting words brought him into Action phase three months later.
I answered with a more personal touch to it and described how one experience in my middle school years basically turned my whole life around. (the answer really blew the interviewer away and he commended me on coming so far in my life and really changing my outlook)
I would address the question to the Interviewer "I would have the research as to why the costs came in high. The possible reasons, time of year, resource availability, etc. If I did not have final say on the cost estimate I would also advise Management of this issue also.