Coming off a CH discussion of restaurant supply stores, I'd recommend checking one out. Here's an example of what you might find: http://www.therestaurantstore.com/Win... These cost $4.59 for a box of 36.
You could also give Fante's a call - they are in the Italian Market in South Philly so they might have a customer base for demitasse spoons. If they don't have them, they can probably recommend someone who does.