It's hard to get more credible than "authentic refurbished Nintendo products" from Nintendo's official store
. Nintendo of America is selling refurbished 3DS and DSi consoles, starting at $100 for Metallic Rose and Midnight Blue DSi XLs, and $130 for the 3DS in Aqua Blue and Midnight Purple.
Nintendo's blurb says its line represents "the only refurbished products in the market that have been cleaned, tested, and inspected to meet Nintendo's high standards." Well then
. The portables have a one year warranty and are guaranteed to work, even if there are any "minor cosmetic blemishes."
Alas, Eurofriends, it seems this one's a NoA thing. "We currently have no plans and have made no announcements for this type of activity in Europe," Nintendo UK told Eurogamer