I bought a set of the cheap ones on eBay (TopSpeed, Godspeed, junk)... They rusted and squeaked horribly after a year or two so I searched for a replacement. I thought that Tarrett or Rennline options were most reasonably priced options from a quality vendor. ~$375.
After a closer look I realized that most of the components are off the shelf, but the expander bolt and spacers are custom. The rod ends are TRW and the heim joints are from FK Bearings. So I ended up making a project out of it and made my own set.