The wedding is going to have to guarantee a minimum number of guests, probably 50. There is a minimum "threshold" of meal and drink expenses for the venue.
What happens if they send out 60 invitations and get 30 Nos? People who said they'd like to attend may reply NO. Particularly when they find out the cost for the room is $100 more then expected. What happens when you assume people who said yes will still say yes when it's time to respond. When it's time to give a credit card to reserve the room.
A wedding at this venue is going to be expensive.
You pay the minimum threshold that's what happens. We did not meet the minimum due to more no's than expected and even no-shows (now that's tacky). We picked a place that we could afford the minimum (regardless of how many people showed up). We didn't provide champagne for the toast. It was $4 a glass and I had a budget to stick to. The Dj made an announcement a few minutes before the toast for people to please get their drink of choice for the toast. To this day, we still have friends and family that thought this was one of the best weddings they have ever been to. We were dancing all night long and enjoying ourselves. We weren't trying to impress anybody. It was our wedding and our day and, this might be selfish, but we didn't really care what the guests thought. Of course, we hoped they had a great time but the thought never crossed my mind that it might be tacky if we had a cash bar. But, then again, we only invited close family and friends. People that cared about us and genuinely wanted to be a part of our special day. The hotel for the night was $165 and this was the discounted rate 11 years ago. We live in a big tourist area. I included alternate accommodations in the invitations in case people wanted to book a less expensive hotel.
Good luck.