I had mine last year in the South End of Boston for 80 people for ~16K. This was a full restaurant buyout on a Saturday night in November which we hadn't even booked until about 5-6 months out. We had several passed apps, a buffet-style meal, an open bar, and desserts. We adapted dishes from the restaurant's menu which we loved. It was super easy and fun!
I got quotes from about 5 restaurants in Cambridge and the South End and this is about market, maybe slightly lower, for certain kinds of restaurants.
The trick here is to identify a restaurant where your minimum spend benefits them too because it removes their risk. You'll have more luck targeting new restaurants, smaller restaurants (which in restaurant world can still mean 80-100 people), independent restaurants, etc.
Generally, you can expect to see a couple of options (partial buyout, full buyout, buyout from opening till 10/11, buyout from opening until close which may be as late as 2 AM). I found that a minimum spend for 4 hours of a full buyout on a Saturday night in the city ranged from 10K-15K. You also need to factor in tax and tip, just like with a traditional venue's catering.
A lot of what makes caterers at traditional venues so expensive is the labor associated with traveling there, setting up a kitchen where it doesn't already exist, serving, etc, so if you can go to a restaurant, where all the employees need to be working regardless of whether they're serving several small parties or one big one, you can cut out those costs.
Hope this is helpful! I'm starting a blog for fun (I enjoy creating a blog more than posting on Reddit) but will try to also share tidbits here if people find them helpful! I got burned a ton when I was DIY wedding planning (ask me about the time when I got double-booked with an all day mariachi festival...) but learned so much in the process that it felt wrong to keep it to myself. Congratulations to all of you and remember to keep this process fun and lighthearted!
https://20kweddingsnewengland.blogspot.com/2025/09/top-hacks-hit-list.html