I have a few extra Nintendo 3DS XL Retail Display Systems for those that might be interested. These comes from various stores like Best Buy, Target, Walmart, Gamestop and so as part of their 3DS Kiosks. 

They all work and have been tested, these don't have a battery built in as they are made to be plugged in at all times to work.

I have 3 different colors of the Nintendo 3DS XL's, the Blue has the Retail Display logo embedded into the system while the Red and Black have stickers attached to the bottom. 

There is also a New Nintendo 3DS version but that one has no markings on them but work the same way.

Asking 75 each plus shipping, cheaper on the three of them that are missing the circle pads.