From what I can tell reading other threads, it seems the Haltech is just a rebranded GM unit, so you're paying a lot for the brand name.
Online it's around the $200 mark actually so far more than these ebay ones.
I just don't want to skimp on something so crucial but also don't want to make the mistake of paying through the roof for a rebranded part.
Hopefully a few guys will jump in here and link me to their ebay purchases they were happy with or something else.