The best trackball ever and it's discontinued.

Belatedly, I just discovered that Microsoft discontinued their Trackball Explorer sometime back in April of this year.  My work purchased one for me several years ago and it has been the best input device I've ever used.    It is right handed by design, so a lefty wouldn't like it, but the placement of the finger tip oriented ball and thumb oriented button and scroll wheel is fantastic.  I tried one of their new designs, which reversed the orientation where the trackball was thumb oriented and it felt completely awkward.  

I've had to resort to using EBay to acquire a used one for home, where you'll pay upward of $120 for an item that had an original suggested value of $70, which is completely odd in the tech world where I'm used to prices dropping as they get older.   The only other time I've paid high prices for old items is when I got the stupid notion that I wanted to max out an old system that used EDO DIMM's.