You seem to have a really comprehensive cost break down. When planning family reunions, you have to really think about all cost that you could incur. I think its a good idea to send out an estimated cost list so family members will have an idea about how the money is going to be spent.

When we planned our family reunion several years ago. We calculated cost for postage, banquet (including taxes and gratuities), food for picnic, picnic shelter rental, T shirts, program booklets, beverages, snacks, paper plates, cups, napkins, awards, and door prizes.

Also when you final have your reunion, see if you can find time to have a business meeting and meet with family members. Provide them with a cost report of what you actually spent and then they will know you are not pulling their leg.