Grad party
Having grad party with two other families and we think about 150 people from 1-4 pm would you stick to appetizers? if so we would include veggie and fruit trays along with brownies, cookies, and cupcake many apps would you suggest?
For grad party with above items, 3-4 heavy dips, some with bread, some with chips; 4-6 other items, amunts depend on what you pick. A really good punch (cheaper than brand soda). Write back,

Or how about a Nacho bar?

decided on dessert bar now the fun question how do you know how much to serve; we will have a chocolate fountain, candy buffet, cupcake display (how many?), and then assorted other that is where I am stuck on amounts.
Look at the chocolate fountain article for the amounts.
Cupcakes, about 2 per person.
Candy buffet, depends on the types of candy, 4-6 ounces per person. There are mnay articles on candy bars across the webs.