When considering what you want your website to look like, always keep the end user in mind. It is your website that you are designing or having designed, but the website is being made and designed not for you but for those you want to visit and interact with the website, so your demographic is very important.
Consider factors like font size (maybe larger for certain audiences), ease of navigation, visual guides and prompts that help the user reach their end goal. What is the end goal you want your customer to reach. There should be a specific roadmap to that goal and if you would like to suggest things along the way that should also be considered.
Grocery stores are laid out a certain way for a reason. The milk, eggs and other products are usually in a similar place throughout stores and that is usually in the back. This is done because these items are the most purchased and to get to them a consumer must pass by a large amount of other items.
In this same thought on sale items or overstocked items are presented up front in large quantities. Seasonal items are displayed in this manner also. Your website can be informational but it is always trying to display some information that is important for the use to see. This is never more important than when you are trying to sell merchandise.
So is design important – ABSOLUTELY! However a sophisticated design may not always be the most effective solution.