DIY here....I recently built two stands to hold 2 monitors each (my ASP8's and Yammie MSP5's). I could have built 4 separate stands but figured it'd be easier to build two wider stands instead. I'll be able to post some pics in a week or two when my new place is fully setup but each stand basically has 2 wide PVC pipes side by side on it with wooden shelves for the tops and bottoms of the stand. They're similar in design to the pic in the link posted above but about double the width to handle 2 monitors on each. The pipes are also a lot thicker.
Each stands consists of 2 x PVC pipes filled with 10kg of sand (in each pipe). To hold the sand in, I also bought some PVC end pieces and just screwed these to the wooden shelves. I also glued some thick rubber sheets to the bottom to decouple them from the floor and spray painted the PVC pipes deep/dark red which looks ok with the cherrywood tops and bottoms. They stand about 110-115cms high.
All up it cost me less than $100 AUD ($75 USD) and about 90 minutes to build them.