How big would this machine be?
You can get small ones from newegg.com, like this one (http://www.newegg.com/Product/Product.aspx?gclid=CPCGn8_18bsCFWQOOgodexAAIQ&Item=288-0009-00039&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-3D+Printers-_-288-0009-00039&ef_id=TdZPhXtOQGEAAMrZ:20140109202114:s) for about $1,300:
(http://images10.newegg.com/productimage/288-0009-00039-01.jpg)
Its dimensions are: 10" x 10" x 13" w/o cartridge.
Then there's this from zcorp, the ZPrinter 850 (http://www.zcorp.com/en/Products/3D-Printers/ZPrinter-850/spage.aspx), for :
(http://www.zcorp.com/images/3248_Z%20Printer%20850-0139.jpg)
Its dimensions are: 47 x 46 x 68 inches (119 x 116 x 162 cm).
And on up from there.