Redesigns are more efficient
Redesigning a website using tables is significantly slower than redesigning a website using CSS. As we mentioned earlier, table-based designs mix visual data with content. On the other hand, CSS-based designs separate visual data from content. By separating the visual data from the content, a web designer is able to easily make changes to the appearance of a single page (or multiple pages) by simply editing the external CSS style sheet. This is one of the biggest strengths of using CSS style sheets: Universal, site-wide updating. More on Universal updating later in the article.
Redesigns are less expensive
Have you ever heard the phrase, "Time is Money"? This phrase can be applied to redesigning a website. Assuming you are familiar with CSS and some of the browser specific bugs that unfortunately come with it, redesigning a website using CSS should take much less time than redesigning a website using tables. If you're paying someone by the hour, then you will most likely find yourself paying less if the designer(s) is redesigning your website using CSS (simply because it shouldn't take them as long compared to redesigning a website using tables).