It's a good idea in theory, but I don't think open bars work like that, unfortunately. Open bars operate on the head count with payment for both for the alcohol as well as paying the bartender's wages and tips. If we wanted an open bar, we would need to pay for everyone, not just people opting in.

I am wary of an open bar because I don't want people to have a free ticket to getting troutfaced and crazy, but if people want to chip in for an open bar for everyone, I will look into it. Even then, it wouldn't be totally open - there would be a cash limit. I was thinking that if we had leftover donations after venue, food, and awards, we could offer drink tickets or something, or give them away in some sort of raffle at the time of the event, idk.

In doing some research on prices, I've read that open bars usually range from $17 - $35 a head. Even if we got the best deal at $17 a head, with a 50 person attendance that still puts us as $850 for the cost of an open bar. I have no idea if this includes the bartender's wages and tips or no. Unless we get some incredibly charitable benefactor to donate a ridiculous amount of money, I am thinking that it is probably not an option.

Or, we could tack it onto the cost of the buy-in ticket. Tentatively, without looking at buffet prices for hotels or anything yet, $25 per person seems reasonable. We could tack the open bar onto that, but then people are looking at paying close to $50 just for attendance for this thing. And then what if not everyone opts to help pay for the open bar? Of course, maybe this is something people want to pay for instead of racking up potentially more money for drinks.

But also keep in mind that if people are coming from all over the world to meet, there will likely not just be a once-only meeting during the week; I am sure we would be able to get together somewhere where we could just buy alcohol by the bottle, making it a million times cheaper for everyone to drink and have a good time.

tl;dr - If people want to pay to fund an entire open bar, I will try facilitate it, but don't be disappointed if it doesn't happen because it is a long shot. Let's hear some feedback on it!

Sorry to keep shooting you down, girl xD These are all awesome brainstorming, though, and I hope you won't be discouraged.