If you are looking to buy a 3d printer as a business investment/opportunity, let me know. I'm exploring that market and would like to talk to people with the same mindset.
Note that 3D printing is a huge, huge industry. Due to how it will allow companies to print or buy parts for their machinery at a fraction of the current costs.
I dunno, 3D printed ABS parts are nowhere near the injection moulding strength of ABS. The construction of a part tends to be porous, and the inter filament bonds are weak. Geometry alone suggests layering tubes ontop of tubes is not the best way to make a strong solid. If a machine keeps breaking due to wear you don't want to replace its metal parts with ultra fragile plastic parts. Maybe it depends on the machine a bit.
I seen people try to make a usable prop shaft out of 3D printing, it broke immediately.
I have built three 3D printers so far and a CNC. I like the CNC best and am designing my second. I use shapeways over using any of the 3D printers I have to hand, if the purpose is to build a working part (or the CNC).
I am in the process of acquiring a 3D printing machine because I have some factories interested in buying plastic parts from me. These are not for precise machining, but mostly maintenance parts. You don't need to compete with CNC machining, because there are so many things you can do with this that its ridiculous.
Note that 3D printing is a huge, huge industry. Due to how it will allow companies to print or buy parts for their machinery at a fraction of the current costs.