With good small machine tool to get very precise cuts at the scale your talking about will require fine tuning it to remove as much backlash as possible. You can get the Taig's backlash down to 0.0005" which is probably about as good as any other small mill in the same price range.
The Taig spindle is very precise, I just used one to drill a 0.096" hole in a small wave guide (RF). The hole had to have precisely square edges, no burrs or deburring marks allowed. I used a new carbide bit and backed up the backside of the hole with a small strip of aluminum. The little Taig did a perfect job according the the customer.
In your price range I think the Taig would provide the most mill for the dollar spent in terms of utility and durability. (But hey I'm a Taig dealer so I am a bit biased
)
You should also consider the quality of control / drive you will be using. If I might humbly suggest you look here:
http://cnczone.com/CNCPartsPage4.aspx
With any collet system you will have to set the tool height with each bit change. You can get 1/8" shank carbide tooling with depth rings installed that will keep each tool withing +- 0.001" or so. You can also use solid tool holders such as:
http://cnczone.com/A2Z_ToolHolder.aspx, they screw on in place of the collet nut. You do have to set each tool up precisely in the holders with the same protrusion though. With Mach 3 you can also use a tool setting probe/macro that will touch the tool down on the touch plate and reset the Z axis to zero the tool.