Totally depends on what you want the site to do.
Do you need Continuing SEO, link management, and hosting included?
I would say $100, $500, won't get you much, and it certainly won't get you the included services that you need for your site to be successful.(if you only have a $100 budget, just build it yourself with any one of free services, templates, or hosting companies, however, you will consult a pro sooner or later when it doesn't produce any results)
Building the site is just the first step. Getting it seen, traffic, and conversions ,or action is the big picture.
I recommend getting it done right the first time, or you will be continually trying to "fix" it, which will cost you more money in the long run and lost productivity time.
A good number of my new clients are, "what was done wrong, and can you "fix" it?".
The bottom line is, you can't get good work, and support done the right way with the service and consulting that you are going to need for the growth of your company, for cheap.
You get what you pay for, and of course, who you pay.
I would look for a company that offers all inclusive services that can help you grow in what ever direction you need to go over time, not just someone who will build you a site, and drop it in your lap.
A $100 website is a waste of money.
JMO