After years of fighting wind and anchors on 20ft pontoon, I've decided to invest in a trolling motor with some sort of spot lock. Is there a way to do this on a budget? Looks like a new setup runs around 1500. What's the cheapest way to get this? Can I buy an older used motor and update it? Also what size would you suggest for my boat? My main need is the spot lock and the auto pilot would be nice so I could start trolling alone and sit in the back of the boat.

Thanks.