Oh, I love driving over the Newport Bridge everyday and seeing this amazing house! I have NO substantive advice, but wow! Enjoy!

Well, you've done Italian, Thai, and Mexican. How about French? A big batch of ratatouille served with couscous is a crowd-pleaser. Socca (am I spelling that right? one c?) for an appetizer.

Gumbo! Seafood, chicken, and veggie versions. Serve with bread, rice and green salad, fruit for dessert. I did that for my wedding, serving roughly the same number of people, and it was a huge hit.

This for the vegetarians:

http://www.nytimes.com/2006/03/01/dining/011nrex.html

(I find it cooks longer than the recipe says)

This for the meat eaters:

http://www.nytimes.com/2006/03/01/dining/011mrex.html

(I use preserved lemons for a more complex flavour)

Both are even better if made ahead of time and let sit a day or two.

Serve with couscous, maybe a Morroccan carrot salad, grilled vegetables, Morroccan mint tea...

hmm, funny how those links don't come up...

The chicken one is a recipe from the minimalist, Chicken with Green Olives. The vegetarian ones is a Nigella recipe, Sweet Potato and Chickpea Curry (with tamarind and coconut milk, so more Indian than Morroccan).

I really love the couscous idea. It would be so easy to make in large portions and would be a real crowd pleaser.

My family used to have an annual "work weekend" too for our shared family house. I always volunteered for house-painting duty. I love cmcinnyc's idea of ratatouille; I also suggest a big pot of chili (or two pots if one is vegetarian and one has meat) if you want something a little heartier after all that hard work. Serve with cornbread and lots of fixins (cheese, sour cream, avocado, etc.).

How about African? There was a story a while back on thekitchn about someone serving a peanut/vegetable stew that looked amazing to me, and was pretty inexpensive:

http://www.thekitchn.com/thekitchn/conscientious-cook/marias-79-dining-for-women-dinner-party--080519

And here's another version: http://www.thekitchn.com/thekitchn/slinks/soup-of-the-day-east-african-groundnut-074836

I will also second the cajun/creole idea. All of the following are great for big groups and inexpensive: red beans and rice, jambalaya/pastalaya, gumbo, etc.

How about Basil Shrimp with Orzo & Feta? It has asparagus and cherry tomatoes so its really light, summery and colorful. If you don't like feta you can switch it for goat which I've done before. I've made it both in the oven and in a pot (just making sure to stir) so I don't think it would be an issue to multiply for a big group. You can find it on Cooking Light.

I second the chili idea. And why bother with two versions when you can make such a flavorful vegetarian one? Maybe make some cornbread ahead or bring along corn/flour tortillas and sides for tacos/burritos.

Jambalaya! With Salad and Dessert for 40, I made it for only $120.

sticking w/ the cajun theme of the jambalaya and gumbo recipes suggested above: red beans and rice. delicious, and can't get any cheaper than that!

Paella.

A variety of quiches along with a big salad. You could buy most of the ingredients in bulk.

Pulled pork sandwiches, use a cheap pork butt make the meat in the oven all day, do some portabello mushrooms for the veggies with grilled corn.

fallafels. Pita, taboulleh. Humus.

Ethiopian
chicken stew (doro wat), lentil stew ( Mesir Wat), a stack of bread (injera), a sweet bread and fruit in wine for desert, sweetened wine (Tej Honey Wine )and pickled vegetables to start - easy, cheap - delicious
recipes here: http://www.ethiopianrestaurant.com/recipes.html

Also in conjunction with the chili idea, a baked potato bar is fun, easy, and cheap.

stuffed zucchini - rice, a little meat, tomato, parseley, all stuffed inside suzzhini and cooked with a broth of cooked onions with tomato paste and water. sour cream on the side.

yum yum

I would do a Moroccan chickpea stew, like this one from Smitten Kitchen: http://smittenkitchen.com/2009/01/squash-and-chickpea-moroccan-stew/

I'm not a big fan of couscous, but it's probably the side dish that makes the most sense here. Otherwise, sub in rice or flatbread.

i know i know. you just asked for a middle eastern recipe but i made mac n cheese for less than $10 for about sixty people last week! Couscous can be fun to experiment with and cheap too! I made eggplant and tomato couscous, with a hint of spices and lemon!

My first idea, it turns out, is also Faith's idea: Middle Eastern mezze is a great inexpensive, flavorful way to serve a large group, especially if there's a large vegetarian contingent. Even better, most of it can be made ahead, which always comes in handy when catering to a crowd.

I'd suggest:
- hummus or some variation. White bean dip with basil isn't especially authentic, but it is especially delicious in summer, when the basil is bursting up everywhere.
- baba ghanoush, which is particularly luscious when you split the eggplants, oil and salt them, then grill (or even roast) them and --- this is crucial for me --- put them in a colander and let a bit of the watery juice drain out. Then process with lemon, olive oil, and garlic. I mix in plenty of parsley to brighten the flavor, too!
- chunks of feta or some similar locally available cheese, and plenty of olives. This is a good place to splurge!
- a big salad with plenty of summer vegetables: sliced cucumbers (salted and drained so they don't get soggy), tomatoes, green onions or red onions, whatever else looks good at the market. I like a lemon dressing with a hint of garlic, but I don't claim it's authentic.
- tabbouleh. Don't be stingy with the parsley!
- homemade pita bread is surprisingly easy and very inexpensive. For a crowd, I'd make it several big batches and freeze each as I finished, so you aren't trying to finish it all the night before the event.
- I like to add one hot dish even in summer. Homemade spanakopita is time-consuming, but it freezes beautifully. You can transport it to the site in a cooler and bake it, still frozen. (We did this for our wedding and it worked like a dream!)

And if you want to add meat to this assortment, it's easy to do. You can choose anything that appeals: chicken, seafood, pork, whatever. If you can grill it, all the better! Serve with a yogurt sauce.

Whatever you choose to serve, good luck and enjoy the weekend!

Thanks for the suggestions everyone! I had to commit to a plan before I read most of these. My kids love my mac and cheese so much, I could make it in my sleep, so we went for it this year. One had roasted tomatoes and bacon, another had kale and roasted tomatoes and then we had a plain one for the kiddies. The salad was beautiful and varied to make up for the simple dinner--lots of roasted peppers and chive blossoms and radishes. I will be saving all these suggestions for the many years to come. I think Middle Eastern is definitely up for next year.

I think your budget for that amount of people is totally dooable. Just this past weekend my friends and I cooked at a women's shelter for 120 people for $200. The dishes weren't anything uber high-end or organic but delicious none the less. We cubed chicken and marinated it in garlic, evoo, and lemon juice. The chicken was skewered with peppers, mushrooms and onions and served with salad and brown rice seasoned with some lemon juice. We would have liked to add hummus to the dish but that would take us over the budget. You could do something like that and maybe add hummus, pita bread and a taziki sauce. I think you can feed your group very well, you just have to plan well.