It’s not that bad to get but you’ll need a council DA and the right facilities (mostly toilets). If those aren’t near town, setting up a septic system can get pricey. You’ll also need a decent public liability policy.
The tricky part comes with wet weather for a lot of these, so you might have to budget for a big marquee or a large building.
And then there’s noise (yes, even on 400 acres) wi th neighbors think fireworks and other stuff your guests will ask for .
So it’s not impossible, just a few things to think about.