Most hosting companies offer templates that you can alter the colour, banner, navigation and such that are on their server. They are usually free so dont expect too much from them.

Or if you want to go down the ecommerce route then there are free ecommerce software out there. Try Cube or The osCommerce These will offer you a massive amount of templates that are freely available on the web. If you started with one of these, you can set up your site with the option to sell items at a later date.

Andrew