In all Website Builder plans any data transmitted from your site will be encrypted using a SSL (Secure Sockets Layer) certificate. Your SSL will establish an encrypted link between your web server and the browser of the person visiting your site. This means that all data will be kept private; which is important if you want visitors to your site to be safe. If you want to sell products or services in your store, you will want to have a SSL since it protects credit card and bank numbers from being intercepted by hackers.
A dedicated server will likely cost you more than $100 per month; it's definitely not cheap web hosting. The benefit? Your website lives on a server all by its lonesome, so it takes advantage of the server's full resources. You'll probably need to handle firewalls, updates, and maintenance yourself, however, unless you opt for a managed server, which costs even more money.