1. You will require a second dedicated server - a Webserver - to host your Website. Allowing public access from the Internet to your business server, and potentially your business and private data, is not recommended;
2. Your Webserver must be running 24/7 otherwise your Internet presence will not be available to potential clients;
3. The costs associated with adding a second server to your IT infrastructure will be significant in both hardware and software;
4. Webserver maintenance will be your responsibility - faults and failures may result in your Webserver (and Website) being offline for an extended period while you diagnose and perhaps organise replacement hardware; and
5. Webserver backup and restoration plans will need to be added to your business processes.

All of the points above are mitigated by using a hosting provider. Hosting fees start at AU$15.00 per month and responsibility of the Webserver moves to your hosting provider. It is likely to cost you more in electricity costs alone if you run your own Webserver.