Does this system of quoting work seem unethical to you? (details inside)

I had a meeting with a potential client where we talked about a project. Towards the end I gave her a time and price range I thought we could do the work in, explained hourly rates and what was included, and said we’d do everything we could to keep it in that range with the understanding that if the project scope changed then we could talk it through to see how that would affect costs. I try to be as transparent as possible. She seemed happy with the range and said it was “doable” and she’d be in touch.

The next day she emailed me saying her boss had requested a firm quote, so a set price. I responded with a set price that was towards the top of the range we had discussed and explained I usually figure in a little time for the unexpected on hard quotes.

She was upset that I “padded” our price and let me know. Her point was that if the scope of the project changed she could understand the price changing, but there shouldn’t be any padding built in.

Since she was happy with the price previously, I have to assume it’s the perception of “padding” that is the problem.

So, if you imagine a project you’re paying for, whether it’s a fence being built, work on your car, or someone to build your next home, do you expect some sort of uncertainty built into a set quote?

Do you find that “padding” unethical?