I've found the AGR rate to be the same as the Enterprise.com rate. So while I haven't had the experience of the OP in terms of getting quoted a higher rate, I've also not seen the AGR rate to be discounted, as AGR Insider implies in Post #2.
In fact, since I have not found a way to receive AGR points while getting a discount using another code (Entertainment Book, to name just one), then effectively I have to choose between getting AGR points or saving actual money using another discount code. The points are nice, but....
If anyone has figured out to get AGR points and apply an actual discount code, please post here.