Agree, Code 3 can not be finaced, therefore the lower price.
The Insurance Industry Have NO hard and fast rules as to when a vehicle or bike is made a Code 2 or Code 3,
I have seen bikes with purely superficial dakage, i.e plastics and it ends up a Code 3. And then you will find a Bike with broken front forks, bent frame, and it ends up a Code 2.
Same with cars, some cars with Airbags activated (So the Dash is Destoyed) and theys still end up Code 2.
Always be very careful. a Code 3 can be a real option as you can buy a bike that is in perfect condition for a lot less than book value. especially if you want to keep it for yourself long term. Just make sure you know who did the work on the bike. It is also a lot more difficult to hide things on a bike.
Cars are a lot more suspect as there are a lot that the eye can not see.
Common sense prevails.
If it is too cheap to be true, it mostly is suspect.