You could score a better deal with refurbished units straight from the source
The biggest argument against pre-owned game and hardware sales is that the publisher or manufacturer doesn't see a single cent of that revenue. One solution is for the original companies to start selling used goods themselves, but how exactly would they set up a streamlined buyback program to amass a secondhand supply? Clearly not as simple as it sounds.
Ignoring the logistics of such an operation for now, it's very easy to forget that this already happens albeit on a much smaller scale. It completely slipped my mind until Ars Technica posted this article, but hardware manufacturers often wind up with a stack of leftover consoles in their repair centers. Those get fixed up and sold right back to you via their online stores.
Nintendo, Sony, and Microsoft all sell refurbished consoles, at much better prices and in much nicer condition than whatever you'd typically find at used retailers. For example, Nintendo has refurbished 3DS units for $129.99, compared to $159.99 at GameStop. That price includes all the pack-in manuals and accessories as well as a one-year warranty, just like a brand new device. Sony's PS3s likewise come with a full one-year warranty, but Microsoft loses points by only offering a 90-day warranty with the 360. For shame!
It's not a perfect system, of course. The manufacturers only sell a limited supply of refurbs -- Nintendo currently only has a few 3DS and DSi XL colors available, and no home consoles. Still, cutting out the middleman does have its advantages. Definitely an option to consider if you are a price-sensitive shopper.
I would like to see at least one of the Big 3 go whole hog on the per-owned market. How awesome would it be if Nintendo started selling hardware and software from its golden years? I would be much more inclined to buy an NES cart than a relatively overpriced Virtual Console re-release.
Nintendo undercutting Gamestop on refurbished portable hardware [Ars Technica via NeoGAF]