I've wanted a CNC mill for a long time, but could never justify the expense. Now there are products like the MakerSlide linear rail system that made it possible for low cost machines. The first round of kits were only $200 for the entire mechanical platform - add your electronics and a dremel tool and the machine can start cutting.
So thats what I did.
The stock kit plus motors after assembly:
One of the nice things about the ShapeOko is how hackable it is. For instance if you want to make the cutting area larger you can just replace the MakerSlide with longer rails. So I added longer rails, a second Y-axis motor, a torsion box to mount everything on, a bigger router and some woodworking T-slot to hold work. Here is a picture of the machine a few weeks ago while cutting a large aluminum part for another project:
The current cost of the machine is $663.75, that includes all components bought for the machine regardless of whether or not they were used and shipping. So far I've spent another $150.55 on endmill of various sizes for for cutting various materials.