Today a former master thesis student showed up at our lab with homemade OpenShoe casing in his hand. He hade bought a 3D printer (http://www.ultimaker.com/), assembled it and printed the casing the same evening. He estimated the cost for printing a casing to around €1. Pretty impressive!
We have been considering buying a 3D printer for quite some time now so I guess we are now running short of excuses.