On USED guns, many of you have a point.
However, for NEW guns, in most cases, the P.O.R. reflects a legal conundrum!
You ask why?
Several years ago there was a court ruling basically allowing Manufacturers, should they wish, to require their retail customers to only advertise price when it was the "Suggested Retail Price". If the retailers didn't follow this requirement, the manufacturers could basically cut off their supply.
The basic idea from the manufacturers standpoint was to keep the "image" of their products at some controlled level and not allow the "image" to be damaged by rampent discounting.
The retailers then resorted to the stratagem of using P.O.R. as a way of letting consumers know that they might be willing to sell at below "Suggested Retail".
Some retailers may be using P.O.R.as a "marketing" tactic, on both new and used guns, but I suspect the "legal" issue is the primary reason for its use.