Your requirements
A simple informational website, something like an online brochure, is a very cost-effective way of obtaining a web presence. This might consist of a main page, one or more additional pages setting out your services or products and a page containing a contact form so people can send you messages, make bookings or whatever.
Depending on the data and photographs used, a site would probably start around $900 plus domain name and hosting costs. If a simple order form is all you need, you can also sell products this way. Sites like this may not need a lot of updating if all that is required is to change a few details or photos now and again, we are happy to do this for you at no extra cost.
Selling products
If you are wanting to sell a range of products from the site, in other words, an online shop, you will need a Shopping Cart.
This site would contain information about your products which would be displayed with photos, description of goods and price if required, posting arrangements and also a method by which clients can order and pay for goods. A site with an online shop would start at $2500.
Costs
As mentioned before, no two sites are the same so it is impossible to estimate accurately what each site will cost without detailed knowledge of your specific requirements.
The only ongoing costs are an annual fee for hosting and the renewal costs of your domain name when necessary.