Forum software - $180+
Domain(s) - $10-20
Host - $24 /year (or more if you want something good)
Skins - Each $25-30+
Misc Items - $10
Having it fail after 3 months. Priceless.
But pretty much, this site has had a lot of money and dedication go through it. People don't like going to free forums from owners who cheap out and rely all on donations.