I really want to start hand cycling, you can get a thing that bolts onto the front of a wheelchair which is 1 wheel, a chain and some handles and it's £2000!!
I can't believe for a minute that it costs that much to make. For a proper Quickie handbike you are looking at £5000.
Someone on a facebook page I'm on has managed to find a seat that goes on the side of their wheelchair for their daughter to sit in, it is really designed to be attached to a buggy so it's about £80 - £90 new.
An equivalent thing for a wheelchair is around £900 and very difficult to get.