I have built websites for small businesses in Santa Cruz since 2011. In that time, we have quoted thousands of projects, and a common piece of feedback is some version of "I found someone who will do it for $500." Sometimes that is the right call. Sometimes it ends up costing more than the “more expensive” option would have.
The price in the proposal is not the cost of a website. The cost is what you spend over the next two or three years in time, lost business, and rebuilding what should have been done right the first time.