I got this very well used and roughed up Matech BUIS from a seller on ebay for $29, shipping included. It looked worse in the pictures than it did upon arrival, so refurbishing it didn't end up being as in depth as I was anticipating. It was a very worthwhile project because the sight ended up looking almost new after everything was said and done and I am very pleased with the results. Check out the video
VIDEO LINK
VIDEO LINK