Saying there is a lot of variation in the field of web development would be a huge understatement. You have everything from anonymous freelancers to large known firms, several hundred dollar budgets to several hundred thousand dollar budgets (and more).
How much does it cost to build a website? what does building a website entails? there are no universal answers to those questions.
Client: "Enough talking, let's get down to business. What will 50$ get me?"
Brad: * looks at wrist watch *
Brad: "About 5 more minutes of my time."
Brad Colbow on Time
In fact, there is so much variation, that a recent client told us post-project completion that when he was shopping around for offers from various firms, he got offers between 2000$ and 60,000$. That's a factor of 30 between offers!
He picked us since we conveyed the best value (quality / price) of all offers, even though he had much cheaper offers (we were about midway in the range). All things being equal, all he had was his gut-feeling and our resume to guide him. That is, if we didn't engage in client development.