I played in a few events in New York where the buy-in was optional, and the top buy-in winners won the cash.
If you're playing multiple spots, I would think that the top 3 out of those who bought in get the cash, meanwhile the top 3, regardless of buy-in the status, win the points.
Having attended your tournament in the new location in the new city, I for one wanted to say I appreciated the prize of a choice of various bags of candy for the top three winners in a non-cash tournament. It could even also be the type of thing as a giveaway for the person/people who get knocked out first in a multi-strike tournament. "Did you come in last? You win a bar of chocolate! Please come back next month."