AdventureX 2018 costs £40 to attend

No those are the absolute basic barebones costs to run, further funds will be used on the event you can see some of the things those funds would be used for in the stretch goals. Profit indicates personal gain.If there is any money left over none of us will spend it, it will sit in a dedicated non profit bank account and used next year.

I think you missed the stretch goals. Also, it’s often typical for annual conferences to carry over some excess in case they come up a little short the following year.

Also, many the costs of the event (I assume) scale with the number of attendees. As long as they have passes left unclaimed, it won’t make sense to say “The event is paid for and all further money is ‘extra’.”