Well this is certainly something BotCon never offered - get up to 25% off your airfare to the host city of TFCon, and in the case of the Chicago TFCon in October, it's from anywhere in the world.

For the TFCon in Canada in July, if you fly with Air Canada, you can get 25% off your flight during certain days (and availability), but you'd just need to get to somewhere first that Air Canada covers.
And for the TFCon in America in October, if you fly with United Airlines from anywhere in the world, you can get 15% off your flights. And they fly from Australia too.
For anyone here planning to go to one of the TFCons this year and are yet to organise travel, go to the link above for the discount codes.