I keep noticing that the cost of used self-steering gears continue to rise. For example, the Navik windvane which used to sell somewhere between $150- $500 dollars is now selling for somewhere between $400-$1000 dollars (check here for a price spread on used Naviks). While it still might be the best deal going for a servo-pendulum windvane the rise in price makes me wonder if it just makes more sense to go with a DIY vane like the Walt Murray 2020B design.
Still, if you find yourself confronted with a used Navik within your price range there is a great article over on Mr Vee on what to look out for when looking at a gear. I should also add that Mr Vee also does some replacement and upgrade parts for the Navik gear.
More info to come as I try and shoehorn my 2020B build into my work schedule…