It's free! In this article we install linux on windows and build our own website. You can access your website from anywhere. Because I will be building my website on Linux so I need to create a virtual machine.
This article explains how to synchronize your database as well as your website's storage directory. Before that, you'd better read "How to Build a Wordpress Website with two Servers".
This article shows you How to load balance your WordPress website. With this method, when one of the two servers has a problem, your website will still work fine. Also, when both servers are in normal state, they will share the load to make your website perform better.