I have a vanilla PHP website that works well. I update the pages in a PHP file, which works fine for me. I wanted to add a blog. Since I'm not a dev, I'll be outsourcing the job. Question is, should I have the whole site rebuilt in WordPress or would a good PHP/WP dev be able to just add the blog, using the existing site look? I'm assuming just adding the blog would be less expensive than starting from scratch and redoing the whole site. What would you do?