With 1000-2000 rounds, there shouldn't be any actual "wear" on the metal surface of the breech face. The "ring" wear you see may just be the finish wear and not actual wear of the metal surface. Brass is much softer than steel used for the slide and is not able to cause scratches or wear marks on the breech face. If you see scratches on breech face, it was done by something other than brass case.
My various Glock/M&P/Sig pistols have 7,500 - 30,000+ rounds through them and the breech faces look slightly less black with the finish wear but the metal surfaces are flat without scratches or "ring" type wear.
Before I consider buying any used firearm, I always closely inspect the inside/outside for wear and parts breakage and insist on range test for proper function and accuracy verification.
I would have someone else more familiar with firearms take a look at the breech face and range test the pistol. If that's not doable, at the very least, feed couple magazines of rounds to ensure the rounds feed and the case base slide up without hanging on the breech face. Ask the seller how the scratches got on the breech face and if the pistol functioned and shot well, would negotiate a lower price insisting that 1000-2000 rounds should not have caused such "damage" to the breech face and must have been something else. If the pistol did not function or shoot well, I would not buy the pistol even at a very low price.
Be careful. There are several reasons why people sell guns and you won't like most of them.
