I completely disagree; you're quoting them the number of hours it will take you complete their project with the understanding that it will be at a certain level

I completely disagree; you're quoting them the number of hours it will take you complete their project with the understanding that it will be at a certain level of quality. As long as you're both on the same page as to the expected quality, how you get to that point is your problem, not the client's. When you bill hours, you do include any time spent sketching some design, or debugging some problem, right? How is ensuring quality in a different fashion and including that time in your quote dishonest?