Don,
I agree NTE can cause conflict, here in Jersey, the consumer laws require, all residential work, to be contract, a known price, before work starts, they don't differ, between, remod, or new work, as for commercial, and industrial, the laws do not apply, they can be either T&M or contract, if you do a T&M job, and the customer is not happy, they have the option of filing, a consumer complaint.