My future in-laws are really annoying me

I love them to death, but I had asked everyone MONTHS ago to give me a final guest count so I'd know how many invitations to order. So they all did, I placed my order, the invitations are now at the calligraphers... today I get an e-mail from FMIL asking if I could add 4 more people to the list. Uh NO, you can't! I'm out of invitations because my mom had forgotten about a few people too! What is up? Did they not take this whole thing seriously or what? My invitations are letterpress so they're super expensive, and I will NOT order more.

And we had told my future in-laws how many people they could invite, and they've gone WAY over that amount. They're inviting friends, children of their friends, neighbors from when they lived in Atlanta 12 years ago, family members of FH's stepmom that FH and I barely know....

It's out of control!!!! My mom has now put some of my cousins on the 'B' list because we've gone way over our guest count

I would have to get back to you on that - it's a crazy amount more than the total number that the hall holds. I think I gave the calligrapher 110 invitations - so if you count that as all couples, that's at least 220 people, and my hall holds 140! And I know the number is more than that, because FFIL decided that he wanted to invite entire families instead of just the parents!!!

ETA: I was told that a lot of these people wouldn't show (from FH's side of the family) because of the cost of traveling involved.