One of the first questions I ask clients is, "What do you have more of - time or money?" and the answer is always of course, Neither. So then the next question is: what can you make more of?
If you have the time you could either build it from scratch using a HTML editor like Dreamweaver. Or build it using online site builder tools that a web host will provide. The online site builders are easier to use without knowing html or FTP settings. But they are limited to the templates that come with the tool.
Many people like the professional look that you get by hiring someone to build the site for you. A nice looking, professional graphic design can go a long way towards adding credibility to your website as a legitimate business. But website owners also want the control to be able to update the site by themselves to change prices, images, specials, etc. Another good thing about hiring a web designer is that they will make the technical decisions for you. All the pieces will work together: domain, host, shopping cart, merchant account, gateway, email configuration, SSL, etc. I'll start writing about these in the next posts.
My advice would be to start simple with your first website. Just build a small number of web pages with a simple graphical design using static pages. Then as you learn how to maintain the website, start experimenting with new things. Your customers will let you know what features they expect in the next revision. As your website business grows, you will see the need for a more dynamic cart with a gateway to automate credit card verifications, blogs or other marketing ideas.
So, be honest when deciding if you have the time to build a website by yourself. If you do, start learning the tools. If you know you should hire a web developer, ask your friends and colleagues for a referral. Lets get started.