I have a friend that is looking for a tandem bicycle. This frameset, 1889 Singer Tandem Trike, would be a nice start to build up a nice rider. It would be a pricey build up though. $14,500 start up, plus paint and parts.
This 1891 Union is a classic example of a very nicely restored bicycle. I have overheard collectors talking of Bob Jameson restoration work, and it is so good that in selling a restored bike, you mention his name and price of the bicycle goes up in value. $19,500
1890''s Bronco style cross frame pneumatic bicycle. With bicycles in it's infancy, there were some weird and wacky designs out there. $8,600.
1883-86 Columbia built 3 Track Tricycle. this was used for racing. It is hard to imagine that with our lightweight, go fast streamlined bicycles of today. $27,500