Update: Sold for $10,200 to unidentified bidder.
The mostly-assembled unit put up for auction on Sunday sports two 30-pin connections, one for docking in the normal portrait orientation and one for landscape, possibly proving that Apple was thinking about releasing the tablet with dual connectors before ultimately scrapping the idea for unknown reasons.
Following the release of the first iPad in April 2010, photos of alleged prototype case backs were leaked showing the standard hole made for the connector near the tablet's home button as well as a corresponding hole on the device's side. At the time it was thought that the parts were prototypes of an upcoming iPad model, but it seems that they were in fact test units for the first-generation tablet.
The device up for auction is a 16GB Wi-Fi only model that has been refurbished by the seller to almost-working condition. According to the listing, all of the internals are original prototype parts except for battery which was replaced after Apple reportedly had it removed. Also missing is the securing clip that holds down the display's flex cable, and the seller notes that the screen's touch functionality is sporadic.
Original iPad prototype auction showing landscape dock connector and internals. | Source: eBay
Adding further legitimacy to the device's pedigree are printed part numbers and a serial number that turns up as invalid in Apple's database. One of the pictures shows what appears to be a circuit board with a date beside Apple branding and part numbers, suggesting that the prototype was made in 2009.
Device running Apple's Switch Board diagnostic software. | Source: eBay
At the time of this writing, the auction remains at $4,800 with one bidder and will end a little after 9pm PST. The seller is offering a "buy it now" option for $10,000 through direct message.