I have been in the web business for about 15 yrs. You get what you pay for, and it is a business. Treat it that way. Here are some things you need to consider.

1) Know exactly what you want. If you don't know, it's hard to convey to a web head.
2) Make a commitment with your designer. This is business and if he/she/it made bad quotes, that's their fault and they live with it.
2) Stay away from Friends or Family. It's hard enough to defend your rights as a client without bringing that baggage into the pile. Just don't do it. The side effects can last a lifetime.

The ecomerce websites I worked on generally start at 50k. It's not all visual. You can guess the quality of the designer when they low ball sites, as they really don't know what it takes to do it or they rely on being able to "adjust" you bill. As an example I am a programmer and worked with the graphic designers. What does it take to support those salaries to get the job done? It's not happening for a couple hundred. For a higher end job it takes manpower and high skills to do it. I code html by hand.

You need to think of it as a business. How much will it take in and how much of an investment is actually required. The rest will be compromises based on real value of the task at hand. Then and only then you can be satisfied with the outcome.