The simple answer is no. We cannot provide a proposal that way and that rarely works out well for either side since there is no way to control costs and keep a project within a set price-range.
That being said, we do offer consulting retainers where you would purchase a block of time that we estimate your project might take, and then we use track our time as we make the changes you may request.
You are an expert in your business and your industry, but probably not an expert in user-experience, user-interface, corporate messaging and design… Our thinking is that if you don’t have the confidence in our abilities before you start your project that it probably won’t get better as the project goes.
We will always tell you what we believe the best course of action is for your project and your business, regardless if it’s what you want to hear or not (occasionally at our peril). Simply agreeing with everything in order to keep you as a client is not providing any value.