Karma Vendor
For level 80 exotics, Orr and the surrounding areas have karma vendors at each cathedral for 42k karma and a variety of stats.
http://dulfy.net/2012/09/08/gw2-templegod-karma-armor-sets/
The only downside is that the dynamic events have to be completed on your server for the vendor to show up. Otherwise, this is one of the most cost effective ways to.get 80 exotics.
The dulfy site also lists karma vendors from maps across Tyria if you’re not looking at level 80 gear yet.