Why do academic conferences cost so much?
My answer to Why do academic conferences cost so much? on Quora
They’re usually a whole lot cheaper than industry conferences, where tickets can cost more than a thousand dollars.
Conferences are extremely expensive to run. Even a mid-sized venue can cost tens of thousands of dollars to book, and larger venues cost even more. Then there’s stuff like AV rental, food and coffee, security staff... and anything that is per attendee (drinks for example) ends up multiplied by several hundred people.
Very few academic conferences operate at a significant profit.