CIS-2014 in Minsk.

Specifically for you, as a Muscovite, it will be 160 euros per hour. And that's without meals or accommodation. For everyone else, it's $60 per day, all-inclusive.

You didn't answer. Are these cheap rooms? How much will the expensive ones cost then? Secondly, does this include the membership fee, or is the fee separate? Thirdly, if, say, 35-40 people arrive (i.e., as usual), where will you get the extra 5-10 rooms at $60 per day? Fourthly, I don't think there will be a queue of people wanting to use this conference hall at the originally stated price. My personal opinion: try to find a backup alternative venue so that you have leverage to influence the administration's pricing policy. As long as you haven't paid a deposit, you can still negotiate. Once you hand over the money, it will become impossible to bargain. And a little bit of arithmetic. Cheap rooms cost $20 per day. That leaves $40. $40 * 45 = $1800 per day for three meals for 45 people and the rental of the hall. Subtract the cost of meals and you get $25 * 45 = $1025 (and I've even overestimated the cost of meals: in reality, few people eat more than twice, especially grilled meat and other things...). $1025 (by the way, the dollar has become more expensive) for the rental of the hall per day.