When it comes to the high-priced website developers, they are going to have a reputation to back them. They are going to have a portfolio of professional websites they have created that are going to speak for their work. High-priced website designers are going to have people who could vouch for them as well as have a very strong web presence. This is the reason why they are going to be priced so expensively, because what you are really paying for is a degree of certainty, not necessarily superior quality.
When you hire a professional web developer to make a website for you, it is also going to cost way more money. There are low-priced developers, and then there are high-priced developers. But no matter what you are going to end up paying way more than what you expect. Each one comes with pros and cons. Low-priced website designers are not going to be that experienced, but that is why their prices are going to be so low. This does not mean that they do not have the skills; they just are not proven enough yet to warrant a high price.