I'm screaming in my head right now, because I can see this easily being done with MDF, PVC tubing (even for the collars and their notches), and a decent table saw (and preferably also a drill press). Just needs the time to cut everything up, glue, drill holes, paint it all, and finish final assembly.
I lack the table saw (and drill press), and space to build it, as my apartment building would not be pleased with the noise.. :-/
With MDF it would be heavy, but the fabrication is pretty repetitive & routine stuff.