[EricH]

Originally Posted by ouellet348

In working we've come to the conclusion that a 3D printer could greatly benefit the team and the shop. We have some budget constraints obviously but there are a few key items we'd love to have.

1. Affordability i.e. $300-600. Total cost excluding extrusion/printing material

[...]

3. Work space. We'd like a minimum of a 6"x6" printable area. The larger the better.

4. Precision. We'd like the capability to objects with a tolerance of +.001", as well as decent regularity in circular and irregular parts.

I think your requirements are mutually exclusive. Either that, or you left a zero off of the price tag. Looking at a basic rep-rap type at http://thefutureis3d.com/store, for a .008" print head, 12"x12" base, $1900 fully assembled (though I think you can work on getting that down if you're willing to do some assembly yourself, and they are looking to sell smaller heads at some point). Looking at the MakerBot machines, it's about the same price or somewhat less but you'll have to cut down on size a little bit.

You could also try a Dimension, but those I think are much higher in terms of both cost and precision. If I'm right and you did miss a zero in your price, I'd look at those first.

As far as durability, that is something that YOU can control at least as well as the machine. Material, print head size, internal structure of the parts, thickness of shells... There are a number of factors that go into durability, many if not all of which you can control.