I'm not very knowledgeable about this yet, but I'm currently helping to co-organize a conference in Greece, and getting some advice from last year's organizers, who did it in the US, and it's amazing how much of stuff they had to deal with (and pay for) in the US that isn't an issue in Greece. Every little thing was possibly illegal, or if legal, required special approval, approved staff, maybe a permit, extra fees, etc., while in Greece it's one all-inclusive price to rent the venue, which comes with a few staff who'll do reasonable odd jobs. And, they're flexible on us doing outside catering or even doing things ourselves (despite Greece's reputation as a worse place to do business). We can even serve wine ourselves, i.e. literally buy wine from the store, bring it in, and have a table where volunteer conference staff pour it, something that wouldn't fly in the US.
Smaller venues in the US are more like that, although I doubt the wine would work. And I've been to one convention (really, that's what these are) at RAI in Amsterdam that was just about as bad as anything I've seen in the US.
Sadly, it's not just the US. I've helped organized events in Denmark, Spain and China and anything involving hotels or conference centers is horrifying expensive.
