There are many good reasons to have a website but ultimately only you can decide if its right for your business. Some points to consider :-
The purpose of having a website is to create more sales for your company. To achieve this your site must be easy to find and essentially this means a search must display your business on the first page of search results. The majority of searches (92% in the UK) are done on Google so your site needs to be "Google friendly". How Google actually ranks pages for placing in search results is not known in detail but there are certain basic techniques to apply that will help obtain a good page ranking.
First the site must be correctly coded so that it validates against World Wide Web Consortium (W3C) Standards. All of my sites are correctly coded and tested to ensure that they pass W3C validation.
All of my sites have these basic techniques applied to give your site standard SEO.
You should note that new sites will take a period of time to gain a search ranking