Depends on what you consider costly. I'd say no though, as I've been to places where the prices are outrageous and Austin isn't nearly as bad as that. Great food though.
With regard to food, it depends on where you go. You can certainly eat for a cheap/reasonable price, but some places are expensive. You may consider pre-planning where you're going to eat by checking out the RT SideQuest Guide to eateries in Austin. Almost all the places listed are local businesses, and most have their menus (and prices) on their websites. Feel free to message me if you have any questions about good places to eat!
Last year we had the eSports arena streamed, and all the panels. It will likely be the same case this year, but we don't have any info for you guys yet.
