Do you wait a week? Do you buy a well built machine with a toy-like build volume or go large? Can I buy it now or is there a lead time? Will it do what I want? Will it print in the material range that I would like? Is it upgradeable? Is the company going to be around 6 months after I purchase my printer?
We're all (unknowingly in most cases) waiting for the breakthrough in 3D printing that will change (or even replace) the manufacturing industry, but somehow we have come to imagine that just being able to afford something that can do some kind of 3D printing at home is that very same breakthrough. Just go to your kitchen food cupboard and ask yourself what kind of machine it would take for you to be able to print and fill all those jars, bottles and containers at home. That's right, you've seen it done on Star Trek. 3D printing is probably the future, but it's mostly not the present. Yet. But I still think you need to get one if you can afford it, if only to enlighten and prepare yourself for tomorrow's 3D technology, which will be able to do what today's machines can only help you dream about.
Why do these home machines matter?
Just as with the PCs, kids everywhere are going to be playing with these things in their garages, learning non-trivial skills that are hard to pick up as an adult, like how to model things in 3D and how to get creative with the limits of fragile materials and layer-by-layer manufacturing. Those kids will grow up and deliver the manufacturing revolution that is the promise—but not yet the reality they caLL 3D printing.