Why use an agency when I can hire a freelancer?

Using a freelancer can be a lot cheaper than using an agency, but there are several pitfalls.

One freelancer does not have the range of skills to provide a properly conceived, designed and built website for a business. Usually the result will be good in one or two respects, and poor in the rest e.g. the site looks great but doesn't work in all browsers and is difficult to manage. Or the site is great, but takes 6 months to deliver (he has got other jobs!).

If your website is important to you, it's always more cost-effective to use an agency.