The price is reasonable as these things go: $95.00 per person x 5 people.

last year for loy krathang some of the dinners at the penn were over $300 per person...

I had the same situation, but in Changmai, Thailand.

I got out of the horrid, overpriced New Year's Eve dinner when I was staying up in Changmai (Suriwongse Hotel-next to the night market-very nice) back in Dec 1998. I didn't know such a practice existed until I showed up at the hotel, one night, a couple of days before New Year's Eve. I was looking for a hotel room as I had to get out of the guest house that I was booked into because it was driving me crazy. I didn't want another night there. So, I walked around Changmai checking places out.
The way I got out of it was that I just walked into a hotel, at night, that I was interested in and asked to see a room. I was shown a room and thought it was just what I was looking for. I then started bargaining the price of the room down as that also had been hiked up due to it being close to New Year's Eve. I simply said that I had no interest in paying for a dinner that I would not be eating.
Then I said to them that if they didn't want to rent me the room, because of me not wanting the dinner, then they could just have a vacant room. I went at night for a reason...better bargaining... Suddenly things changed. The room rate went way down to where I had bargained it down to...from around $75. to $55. and the dinner suddenly was no longer manditory.
I find this manditory Christmas/New Year's Eve dinner practice quite annoying,too and especially since I can't even eat most of the food due to food allergies along with not eating meat/poultry.

So, after becoming aware that such a practice existed, then I booked into places that didn't have the manditory meal. Happy Travels!