Cost will depend on type.
In our area (food is really expensive BUT)
- Big 30 brat package = $9
- OR brats run at $1.50 each
- Turkey dogs are $1.50 for 8
- OR Regular or Kosher dogs are $5 for 8
- $0.88 for buns
- OR $4 for buns
I would personally get 3 packs of 30 brats (2 each) and 10 packs of turkey hotdogs and 1 pack of tofu pups (just to be safe).
90 brats
80 hotdogs
8 tofupups
88 buns
_________
27
12
5
9
____
around $50
I'd also grab a 10lb bag of potatoes and makes potato salad & a couple heads of romaine and make a caesar salad. Also something cheap and easy (like baked beans, homemade is a pain, but dirt cheap OR vegetarian chili... ALSO dirt cheap. People can eat it with, or put it on their dogs for chili dogs. But if there are going to be a lot of kids... I'd nix it and do macaroni salad... because either baked beans or chili can get MESSY, and red doesn't come out that easy))
Bringing my total up to about $60... which, feeding 40 people, is an out and out steal at $1.50 per person
HINT: Hotdogs and brats freeze. Really, really well. If you just open 30 brats and 30 hotdogs to start, and then open as needed, the unopened ones will freeze and you can defrost and use all year long.