My mil Won’t Cut Her Guestlist

My fiancé and I are paying for the wedding ourselves. My second, his first. It’s a destination wedding as we live far from everyone we know, and I asked to keep it small because I don’t feel comfortable with having lots of unfamiliar faces and want just our closest people. The venue is also VERY pricy and designed for a small group (quality over quantity). So, given the budget, the venue, and my personal preference as the bride, we made a list of about 100 guests, including some friends and cousins of my fiancé’s parents to be nice. My goal was to end up with 80 guests max. Then, I found out my fiancé’s mom just went ahead and verbally invited 60 people (I haven’t even told her how many she can invite or invited my own guests!). I’m so hurt and actually livid — she didn’t even offer to pay for a single one, let alone ask permission. I tried to compromise and said a table fits 8, so can you pick one table of friends? She kept me waiting a week and then cut 3 friends, claiming the majority of her guests won’t come so it’s really just 15 (still more than I said!). Now I will have a minimum of two whole tables filled with just her friends, which is probably more than my own since I kept the list very small. I’m honestly shocked at how rude this is. I explained how expensive this wedding is and how I want to keep it small but she didn’t comply, nor did she feel it was worth addressing — no apology or anything. My fiancé can’t say no to her because he says “it’s normal for parents to have friends at a wedding” and feels 15 is an appropriate number. He is not conscious of budget and doesn’t think me wanting an intimate wedding warrants her not having her friends there. I see it totally differently — I don’t think parents need friends at a small destination wedding their kids are paying for, and I don’t think I need to go bankrupt so that she can have them. This is not a big reception hall with mediocre food where you pack in 250 guests for $50-$100 a person. The venue fits 150 guests max and costs $400 a head — I wanted to really treat our closest people to something special, but my fiancé just doesn’t get it and won’t put his foot down with his mom. He says “just cut some of my guests then.” That’s unacceptable to me. I should be spending this extra money on my honeymoon, not so that my mother in law can have more friends than the bride at my wedding. At this point, I want to tell her that if she can’t choose an appropriate number of friends she can’t invite any. What else can I do?? Any advice is so appreciated.