Looking at the official Rohrbaugh website, I see that the warranty only applies to the first owner of guns purchased through licensed dealers. From this, unless we hear otherwise, this would mean that anyone purchasing a lightly used R9 does not have a warranty on it. In the case of a gun that only has had a few rounds put through it, it would not be possible to assume that the gun is free of the rare, but not unheard of factory glitch.
I was wondering if Rohrbaugh would be willing to extend the warranty on lightly used guns to a non-original owner. This would keep the price up on used guns. In the absence of this, I for one, would only buy a used R9 if it were significantly discounted from MSRP or if I knew the original owner and he could vouch for its performance for the first hundred rounds.