Craigslist first, then local listings, if all else fails, ebay.
BTW: I've been shopping
for a small outboard
for a few weeks lately. The ones on craigslist go fast. The ones on ebay usually sell a little higher, but they also have the shipping
charge (which shouldn't be more than about $60 for a 2.5hp). I think the ebay ones are more expensive because the people that are buying
them are not in a location with a lot of boats and stuff for sale
locally... So they happily pay the shipping
on a used motor
I just bought one today, had to act fast since I've seen at least 4 in the past 3 weeks sell on the first day via craigslist.