Perhaps I am wrong, but I have always worked on the premise that a quote is a quote is a quote. If I state a price, then I stick with it, and if a deposit is paid on something, and I accept the deposit, then I am actually legally obligated to honour the deposit. That is in a business sense anyway, I would have thought if someone accepts a deposit, they have entered into a legal contract, whether paper be signed or not. Taking the deposit on the CT would have meant some form of obligation surely.
Regards
Tjupurula