I realize 3 bean salad is fairly inexpensive but I love the stuff and make big bowls of it when I do. Most people have these ingredients and you can use any beans you like although I typically use Canned Green Bean, Wax Beans and Kidney beans. And to fancy it up add Garbonzo beans.
1 cup cider vinegar
1/4 cup vegetable oil
6 tablespoon honey or sugar
1/2 teaspoon ground dry mustard
1/4 teaspoon garlic powder
1/4 teaspoon ground black pepper
1/2 onion sliced
1/4 teaspoon onion powder (optional)
1/4 teaspoon ground cayenne pepper (optional but nice)
Drain the beans and place them in a large bowl. Cover with marinade and refrigerate. I think it is at its best after a couple days.Yum!