I've been using fully adjust monitor arms for a number of years, but they are heavy, and I realized that I never actually adjust them. I decided replace them with something fixed, and this was the solution that I came up with.
The total cost for these monitor arms was about $40, including the glue and all of the screws needed to mount them.
Step 1: Parts
The base of the mount is made of two parts. A flange, and an adapter. The flange is actually for a 3" or 4 " pipe (there were no 2" flanges available), and the adapter goes from 3" to 2".
I also bought some slip connectors so that I could cover the hole from the top, and create a stronger mount. This isn't entirely necessary, and could be left out, especially for smaller monitors.
Step 2: Planning
This adds additional complexity to the design, since the holes must be drilled in exactly the right location, or the monitors won't be located correctly.
This also meant that I had to contend with the frame of the desk, and make adjustments to the location to accommodate the cross member.
This aspect of the design can be changed quite easily so that the flange can be mounted on the top of the desk (as explained in the next step).
The pictures below are of the completed mounts.