Firstly “something is only worth what someone is willing to pay for it” is hogwash because what is something worth when some people are willing to pay ridiculous amounts of money for it and others are not willing to spend much of anything... and it seems to be the exact same thing?
That is the world of web design. In this industry we have completely free sites like Wix and Weebly (you have to do it all yourself, but they are totally free) and then you have firms that charge over ten thousand dollars, and you have every price point in between being charged for a website. And they are all more or less the same.
To the end user, the people who surf the website and even to the company/people which it represents, a website is a website is a website. That means that the value of the website is literally what you are willing to pay for it and that contradicts what we said in our opening paragraph.
So that begs the question... what should you pay for a website? You have probably gotten quotes from a couple different design firms and done some research into what other business owners have paid for theirs, you have probably even heard some (or possibly quite a few) horror stories and you are more confused now than when you started, right?
The answer for you is "it's up to you and your needs".