Well, maybe GRE is price fixing but more likely these small dealers don't want to abandon what little profit they make. It's hard to imagine anyone other than RS that would purchase in sufficient bulk to be able to knock $100 off of list--and even THEY only do it once in a while.
The going rate has been around $500 for top Uniden & RS scanners for quite some time. Considering that the digital scanners involve payment for the rights to decode certain data, we're probably lucky that it hasn't gone up. GRE is a newer player (on its own) in the field, and I can't see them lowballing a product that they've been continally refining for nearly 2 years.
The GRE you buy today is considerably improved (at least in terms of firmware) over the one you bought when they first hit the market. (Oct. 2007, I think) Didn't I see a post here that yet another update was imminent?
And look at Uniden, they issued new firmware for the 396T just as they were about to release a new model. Ongoing R&D for products you've already sold costs money. I just hope they can hold it where it is...
73/Allen (N4JRI)