The Best Rate Program can ONLY be booked online. It may be that the CM to whom you were speaking couldn't even access the BRP prices with her computer and remotely possible that she doesn't even know the difference between BRP and traditional AP discounts.
Generally, the BRP is lower than
AAA which is lower than rack rate. However, BRP is not as low as the discounts that have been offered in the past. I also noted that people who booked recently with the Florida Residents Discount got Moderates for the same price in Dec. that I had gotten through BRP, so if you know your dates, BRP is currently the best price going.