I'm not worried about round counts. Most people I see shooting and selling, even the people I shoot IDPA/IPSC with, put in round counts well below 2000 before selling a gun; if they get over that kind of count, they're usually going to keep the gun. 5000 rounds is nothing in the majority of firearms, save antiques and historical pieces which play by different rules.
I find most people who have a gun that is genuinely used hard are pretty clear about it (I remember some time ago a gent posting his 92FS which had been pretty thoroughly battered in the best way--though use).
"Low round count", "box of ammo", etc. are pretty much in the same category as "shoots like a dream", "great trigger", "very accurate" and so on--they're nothing statements most people don't know how to quantify anyway, and you can safely ignore. Pictures and seller rep are what matter.