Earlier quoted context omitted.
Harsh judgement maybe but to me paying $500 for tickets to a convention about anything is drinking the kool-aid about that thing.
I don't know about all conferences, but in my line of work most conferences cost up to $2000 or even more (for example "late tickets" to a conference I'm attending in June cost $3000). I guess enough people (or rather, employers) consider it valuable enough to pay this price.
As we know, prices that can be expensed out have a tendency to be considerably larger.