When I bought these they were $159. (At a music conference in Knilling rep said the price increased to $179). Regardless, I don't need 5 extra sets so I will sell each set for only $100 plus $5 for shipping and I will accept PayPal or personal check. These are for 4/4 size cellos.
Unless they've come down some since, the price is twice the price of my fiddle, and 1/3 of a very good lap dulcie; but they might be worthwhile if you really wanted them. (And they may be much cheaper now.)
There's a link to "Installation" at the Peghead site that shows the innards of the things (although the picture is low-res). IMO - based on abstracts of the patent only - this should not have been granted a patent, as it's just a not-too-original application of 300 year old (patented and expired) gear designs; but there's a lot of that goin' round, and patents are the province of lawyers, not mechanics.