Bingo Can Someone Explain Large Bingo Events

There is an upcoming event at South Point casino; $250 entry fee with no extras, $101,000 prize pool, 640 max entries (the size of their room). Easy, about 80% RTP.

But I've seen others with like a $495 entry fee for 6 cards, with significant charges for larger packages.

Now, my girlfriend likes to play Bingo, where she plays they have a $6 paper small rainbow and with a couple small extras that makes her happy. She doesn't have much chance of winning but it's possible. So I can "get" a paper-only player who has the max of 12ish cards.

But not for a $495 entry fee just to get in the door.

It seems like if you're going to go, you have to plan to go for Big Money. But if everybody is going for Big Money, then everybody's odds just remain the same.

What's the logic - if there is any?