I have been following the progress of 3D printers for a number of years. These are printers that deposit plastic to create prototypes, etc. Just a few years ago, these printers went for around $30,000 to $50,000. Now you can get kits for as little as $1000 (although sophisticated versions that print color and precise details are still in the $20,000 - $30,000 range). Now these printers have expanded to concrete and other materials and work on a larger scale to create large structures. There is even research on expanding this to "bioprinting" to replicate human tissue and organs, to leather and even meat products.
