I originally created my website 8 years ago and have been very happy with it. Now I want to look at modernising the site and improve its functionality and changing the focus of the content. Ideally I would like to keep the current design and branding. Is it cheaper to amend the site or create a new site from scratch using elements of the design that I already have?

I'm wondering about whether to add a weblog where I can publish a monthly newsletter type feature or perhaps integrate Twitter. I would like to come in contact with a developer who can help me with this.