Check your local boat sales/repair places. I was having some work done on my boat when the tech told me they had a TON of trolling motors to sell cheap. They get them when guys order new boats and then upgrade the TM. Lots of people don't take the older, smaller one because they don't want to hassle with selling them. I have also seen a good number in pawn shops.

Good luck w your search. Be patient and you'll find a deal.