how much does it cost to buy a website?

im interested in started a online retail business and im just wondering how much a website would cost?
when i say buy i dont mean buying an existing website, i'd like to create one

There are 4 main components to a website:
1.Domain name:
You purchase the right to use www.yourname.com on the web. The yourname.com is the domain name. Purchasing this costs roughly $30, give or take a few dollars. There are places to buy them cheaper, who may then charge for changes or transfers or give poor customer service.
2.Hosting:
You pay a website host to keep your website online all the time. They place your graphics and text files on their server, and keep it running 24/7. They will log visits to your website, and run software that allows you to know how many people have come to your site, from where, what pages they visited, and so forth. They may also offer mailing lists, mail aliases (you@yourname.com e-mail which shows up in your AOL mailbox is a mail alias -- think call forwarding).
Hosting can cost from nothing (usually ad-based, or as a freebie with your internet access) on up to hundreds of dollars a year. It depends on how much information you're going to have on your site, how many people will come to it, and the other available services provided along with the hosting. Again, your webmaster will have a relationship with a reliable host who provides good customer service, at an affordable price. Plan on spending $100-$150 a year for most hosts. Freebie hosting is usually a bad idea for a professional site.
3.Design:
This is where most of the start-up cost will come in. What level of graphics do you want -- highly developed, customized just for you? Or something more generic, from a template? How involved are you doing to be in writing the copy? Do you know how you want the pages set up? Do you need help gathering information about your books/cover images? What extras do you want on your site? Do you have permission to use the cover art from your books? Do you know your priorities for getting your site up and running? Do you need help with contests, or mailing lists, or screening e-mail? Your website manager will discuss all of these options with you, as part of the process of outlining your site and determining its proposed cost.
4.Maintenance:
How often do you want it updated? Do you tour? Do you offer interactive pages on your site that need to be monitored? Do you put excerpts online? Reviews/blurbs/links? This is another area in which costs can be controlled to fit your budget. Some authors choose to update their own site once it's been built -- letting your webmaster know this upfront can help everyone do a better job. A professional can update an entire site in less time than it probably takes the average computer user to figure out how things are set up, where they are, and how to make changes and publish them. Maintenance costs are charged hourly, monthly, quarterly, or annually based on the webmaster.