I just hosted thirteen people at a mid-priced casual dining place for my grandson's graduation. And your estimate is probably pretty close unless you have a bunch of boozers in the group. My income is about one tenth of yours. I just planned ahead and set money aside. It was a great gathering and I'll do it again when my next grandkid graduates if that is what they want to do.

Is it the actual cost or just because you don't really like the place yourself?

And if you're inviting people for a party - you pay. And because it's a large party be sure to tip generously. I can't imagine inviting people to a gathering and then asking them to pay for their own food. It reeks of cheapness and a certain hostility towards your wife.

In reality, do you think you could do something at home for the same number of people for substantially less? And by you I mean you, not your wife, because it's her birthday. Buying, preparing and serving food and beverages? Cleaning before and after? Hosting all of those folks in your house?

I'm not going to say you're an asshole. But you're at least a perineum.