I'm kinda new, but how do you know they're duped?
(don't hate on me, I honestly don't have a clue)
The chance of the same item rolling with identical stats is very low. The chance of 4+ items having exactly same stats is infinitesimal. The chance of 15 items having identical stats is astronomical. The chance of multiple items having same stats 15 at a time (remember that mid range trifecta tal ammy ?) is an indication of something happening. Its akin to winning powerball lottery 10 times in a row.
Edit: so yes, to continue. If anyone believes that investing in diablo 3 items is a good idea (even understanding normal depreciation caused by naturally occurring drops) they need to wake up. Blizz did their best to ensure duping will not happen. It wasnt good enough. The economy, as many predicted even before the game launched, will spiral out of control and those who spent their money to gear up can safely consider it a donation to promote hacking botting and duping. With Blizzard, naturally, having a cut of these said donations.
I believe this is so very wrong. I have resisted the urge to bu anything off of rmah from the day it opened, having all the means to do so. Primarily for the reason below, but secondarily due to the "now what..." factor. If i was to get gear from RMAH to advance in the content, i can just buy better gear once again to further advance in the content. There wasn't a goal to reach anymore. I played D3 from release (and beta prior to that) to approximately September of lat year and i still log on once a month or so, do 1-2 alk runs and log off.