For a 35-person seafood boil, I’d plan on a Costco run of crab/shrimp, sausage, potatoes, corn, butter, seasoning, lemons, garlic, and a few disposable extras. A reasonable total is about $300 to $650 , depending on how seafood-heavy you want it and whether you buy premium crab.

Costco shopping list

Here’s a practical buy list for 35 people:

Item| Amount to buy| Rough cost
---|---|---
Costco seafood boil tray or seafood mix| 8–12 lb total| $95–$145
Extra shrimp| 8–10 lb| $80–$140
Crab legs or crab clusters| 8–10 lb| $120–$250
Sausage| 6–8 lb| $30–$55
Red potatoes| 15–20 lb| $10–$20
Corn| 30–40 ears or equivalent frozen packs| $15–$30
Butter| 6–8 lb| $25–$40
Old Bay/Cajun seasoning| 2–4 containers| $10–$25
Lemons| 8–12| $6–$12
Garlic| 4–6 bulbs or minced garlic jars| $6–$15
Onions| 4–6| $4–$10
Optional extras: mushrooms, boiled eggs, disposable gloves, bibs, trays| as needed| $20–$50

Best budget split

If you want the boil to feel full without going overboard, a good mix is:

  • 1 Costco seafood boil tray or premade seafood mix for convenience. Costco’s ready-to-heat seafood boil has shown up around $11.99/lb and includes crab, shrimp, mussels, clams, potatoes, corn, and seasoning.
  • Add extra shrimp and sausage to stretch it.
  • Use potatoes and corn as the cheap volume builders.

That setup usually lands closer to $300–$400 if you keep crab moderate and skip a lot of extras.

Bigger, fancier version

If you want it to feel like a real party boil with lots of crab, expect the price to climb fast because crab is the expensive part. A heavier crab-focused spread can push you into the $500–$650 range pretty easily.

Easy portion guide

A simple way to think about it:

  • Main course with sides: plan roughly 1 to 1.5 lb of shellfish and seafood mix per adult.
  • Add 1/2 lb sausage per 4–5 people.
  • Add about 1 potato and 1/2 to 1 ear of corn per person.

That usually gives enough food for 35 people without running dry.

A practical Costco cart

If you want the most efficient cart, I’d do:

  • 2 large seafood trays or equivalent seafood mix.
  • 1 big shrimp bag.
  • 2 packs sausage.
  • 2 large bags potatoes.
  • 2 big corn packs.
  • Butter, garlic, lemons, onions, seasoning, and disposable serving stuff.

That is the safest “feeds everyone” setup without getting into luxury pricing.

Estimated total

  • Budget boil: $300–$400.
  • Solid crowd-pleaser: $400–$500.
  • Heavy seafood/crab boil: $500–$650+.

TL;DR: For 35 people, expect Costco to cost about $300 to $650 , with $400–$500 being the sweet spot for a good, generous boil.