I'd be super curious to hear other answers on this as I think about budget planning for my next FY haha... but here is what we've had for the last 2 years of scenarios at Mendix:
$40K last year - we hosted it as a single day event in our head office in the Netherlands and all attendees were coming from Europe. Majority of that budget was spent on covering cost of hotel rooms for those who weren't local + our evening dinner / activity. Then we had some attendee gifts, signage, etc.
This year we're bumped up to $100K - a big leap as we've made the event 2 days (so now have 2 nights of dinners to cover) and are inviting customers from other geographies, so supplementing some of their travel costs to make it easier to get there, and also still covering hotel rooms for all who can accept it, and our audience size is nearly doubled.
We still save the most $$ by hosting the event itself in our offices so we dont have to worry about a significant venue cost. Year 1 was 25 attendees, and this year we are targeting 40.
