While the cost of the same website can vary wildly between different design companies, you should do due diligence to make certain you have a team you are comfortable with and your needs are met. The basic site, including about 16 -32 hours or work costs roughly $1,000 - $5,000 for the design phase.
Your domain is relatively cheap, only as much as $25 / year. It is going to be your first charge.
Now you need to host your domain. This will cost your between $2.95 - $70/month. You will have to pay by the year and often multiple years to get anything under $9.95 / year.
Website SSL, from $0 - $1,000 / year.
The actual website design is from $1,000 - $20,000. This higher end would include e-commerce and more. For a truly small business this rate be a lot less, from $1,000 - $10,000.
The floor increases based on extra pages. 10+ pages start above $1,500.
Functionality will also increase the floor cost to above $2,000.
CMS(content management system) will allow you to manage your site with a backend content management system.
Website monthly maintenance can be range from the cost of hosting to $$$, based on the number of hours included per month. I have seen $500, but htis is total tech support.