Just kind of think of Your H S day Proms.
The reason You are getting together is to have fun, intermingle, get down and Funky. Oh, Yes, I am a little older!
A Local Spinner or CD player is cheaper than a Band. Member is a lot cheaper, and can put a stack of CDs on and enjoy the party.
Do a cash bar so the expense is on Your Org.
If eating, maybe can get a caterer or Hotel to give a little break with the room and food.
Does the Wal-Mart have a Grocery Section? If so, do, cold cut and cheese plates, dips and chips, potato salad, and baked beans. Fingure food sounds good but cheaper!
Can get paper products there also and being an employee maybe even a discount!