Yep, the trikes aren't cheap. I wonder if Hannigen would do the front wheels and not the back. A Gold Wing Can-Am? If not then I'd either get a Can-Am or a small sports car.
I've looked at sidecars a lot. I'd like to have one, but.... They don't handle well at all, bike really needs mods to the front end to work well. That is, unless you just want to putt-putt around with one. For just tooling around they are fine. If I am going to change the bike that much then why not get the Can-Am and not have the issues associated with a sidecar. My problem is one of the reasons I like bikes is the performance. Take that away and there's no reason to ride one.