You're in NYC, it's winter. So, profile your client (& guests). Always good to have enough for vegheads to eat.
Depends on equipment, type of service (drop off, full service, plated, buffet, etc)
$8-12 is a nominal budget....so.....
green leafy salad
stew/braise/soup.....ministroni, chicken mirabelle, chicken and dumplings, etc.....
flan or panna cotta or ?