How about the balancing electric wheelchair that is no longer being produced because Johnson & Johnson cannot find a way to profit of off it, yet many people with MS want one?
http://en.wikipedia.org/wiki/IBOT
As of 2006 the iBOT retailed for approximately US$26,100 and required a prescription in the U.S. As of 2009, it is no longer available for sale from Independence Technology, but support for existing units will be available until the end of 2013.