The above post is spot on.
If you can't afford a big dinner out, try something different.
I have a big family gathering about 4-6 times a year. This can mean between 20-50 people to feed.
One of the best meals to feed a crowd is baked pasta. I can feed an army with homemade red sauce and baked rigatoni. Not hard to take off the shelf sauce and change it up a little.
Ive also done beef brisket sandwiches, which costs more, but is still good for crowds as you can keep it hot in a slow cooker.
Look... You are where you are. In the end, the meal isn't going to make or break the marriage. Try to find something that can feed the group, but not break the bank.
Dont feel bad about this.