Cut the number of items for one thing. Keep it simple. Focus on a single main course instead of the half dozen you mentioned. Make sure what you served can be cooked thoroughly and quickly and is popular.
Also focus on one cooking method. Make it the BBQ or the Kitchen, not both. This reduces the problem of what to cook and where the hell the food is. And reduces the numbers of cooks required and the stress on them.
You can get good deals at a butcher or the professional suppliers for hot dog vendors if you are in a major city. They will sell sausages, hot dogs, buns and condiments by the case. I'd go with the hot dogs and sausages. And the kids are happy too because they are eating the same food as the adults. I hate it when there is a difference in fare between kids and adults. It sends a bad message to a family oriented gathering.
Steaks well some want it rare, some want it medium, some want it medium but burnt. Some want fat, no fat, with bone, without bone. One can never get a steak right. Who needs the aggravation?
Here's why focus on only one cooking site. In your original proposal that would have required not only two or three cooking locations but at least five cooks and all those dishes. So while hookie the BBQ with Buns and napkins for dishes makes for a fast cleanup.
Also chicken, shrimp carries the risk of food poisoning if they are not cooked properly. Meatballs can be bomb because people are really opinionated about them. Every one seems has an Aunt Maria who made the most wonderful meatballs. "These will be okay though"
You don't need that. No one criticizes Maria's hot dogs. Even meat loafs are a faux pas on an occasion like this.
Condiments would be a large jar of mustard. Ketchup, A Large jar of Relish, A large Jar of Sauerkraut. You can get those at the hot dog vendor supplier if you manage to get to one. Some even have some prepared salads.
Aim to set a salad bar instead of all those meats. A lot more people nowadays are not into that much meat. Plus you can do salads much cheaper and beforehand. And a salad bar with the three basics Tossed, Bean and Potato allows the people to mix and match their preferences. Have a Pasta salad which all are really cheap to make and quickly replenished if you have to whip back to the store. Just get about five salad dressings, the usual Italian, Thousand, Caesar, in addition mayo in a squirt bottle(s).
Get those small cherry tomatoes, thaw out those baby carrots. Layout a bowl of Pickled Beets, Slice up a bag of Oranges into Quarters to bring color to the Salad Bar. You can really go artsy fartsy in a Salad Bar and few will complain.
Usually people are really happy with Salad Bars and most will remember that instead of the other stuff. And for salads you just need foam or paper bowls with party plastic ware. Again few dishes cuz bowls and salad tongs are really easy to wash.
(Avoid Egg Salad and Tuna Salads since they go bad really quick.)
Get to a bakery and get lots of baked goods and appetizers. Many people will not eat that much in the afternoon. In any case always get a few garlic Italian breads. Lop them into five inch pieces.
This you can bake and buttered with some with cheese on top served at the salad bar when you need and the reason for this is that bread tend to stuff the people up and the quantity of higher value foods last longer. Again with a minimum of dishes other than a baking pan and a serving dish.
You should also break the drinks up. Here you have a secondary problem as a host. Remember you are responsible for getting those people home safely if they drink. For that reason I would not serve more than two beers per guest.
I would also go for punch. Something like a Collins Punch with lots of ice.
A bottle of gin per bowl about three cans of frozen lemonade or something. Slice up some lemons to dump on the surface and remember the sweeter it is the more women like it. The rating of the party depends on the women, no one cares if the men don't or do like the party foods. So slide in a cup or two of sugar.
If you run low its easy to hit the store to replenish. A good size bowl for usually is good get enough for two bowls. Booze is easy to get rid of. Never worry about a surplus.
You can get away with a cheaper gin and a case of frozen lemonade is easy to store after. If the punch runs down too far. Its really good if at the end of the party there is only an inch left on the bottom of the bowl even if you have to sneakily drain extra punch down into another container. Guests like free booze but they also feel good when the punch bowl is almost emptied. Its an ego thing.
Remember what ever you decide use simple fare cooked since it is the easiest to cook. Use a salad bar and breads to supplement since they also keep dishwashing to a minimum and tend to fill people up. And the latter can be prepared before not during the event.
If you got a few bucks left get a couple of boxes of chocolates or chocolate mints to pass around after the meal drags down, Even if people refuse the mints they will be happy that it was offered. And most women like chocolate anything so this easy to serve desert thing sates them easier than fancier deserts.
Those are a few of the more affordable ideas.