Since this website is the bread and butter of the business you need to pay someone to do it. Programming isn't easy and costs time and money. Nobody will do it for free.

If you try to look for someone with the cheapest price you are in for trouble, especially with your limited knowledge of programming. You need quality and you have to pay for it.

Why wasn't the job finished by the person who built the parts?

You also must realize that when you bring someone elses code to another programmer you may have some issues as every programmer does things there own way. If a programmer created the code in a very disorganized manner, you will pay more.

If the code is ok, you will pay around $1500-$2000 to get the site working. If the code sucks, then sometimes it is quicker to have the new programmer reprogram it properly.

Alot of people get screwed when it comes to web development and it is because of lack of knowledge. It sucks but that is the business. People like you come to me all the time after they spent all their money on someone else, so I know how it feels and everyone finds a way to pay because if the business is important enough to you, then you will the the money