I'm voting to close as primarily opinion based but, this is longer than a comment so...
The only camera I've ever sent into repair was a workhorse camera we used when I worked at a photo studio. The kind of place that did portraits all day long, sports all night, and events on weekends. The camera saw constant use for years.
My personal cameras? I've still got a 20D that works perfectly. (Granted, it doesn't see much use these days).
What's really important when buying used is who owned the camera and how did they treat it? Were they a pro using their gear day in and out or an amateur that shot on weekends and holidays?
Did they store the camera well or toss it around? (How's the hotshoe look? Brassing on the edges or where a tripod connects? Dust in the eyepiece? Scratches around the lens mount? Wear and Tear on the strap lugs? Any discolorations?)
The only people who will blow through a shutter while leaving the camera cosmetically perfect are those pros who do so in short order. For most amateurs, the cosmetics will age right along or more so than a shutter.
Typically, I'd say to make sure that you can inspect before you buy. But, since it's eBay, make sure there's a good return no-questions-asked policy so that you can inspect and return if need be.
To answer your question directly: No, I'm not aware of fraudulent shutter count resets, though I wouldn't be surprised if it happened.
