The service is live at http://www.ebay.com/mygadgets.
One thing that is interesting is that eBay (gasp) tracks your purchases. When you login to the site at that link, any past eBay purchases will be noted as part of your inventory. That is, of course, whether you want them to be there or not.
To remove any such items, you only have to click on the "x" seen in the upper right hand corner of the item image when you mouse over it. Notably, and as seen above, the site is perhaps misnamed when called "My Gadgets," as it allows storage and sales of other items besides electronics, such as DVDs (seen above).
To add a device to your catalog, you have to type in the name and search for it. It's important to be precise, as typing "Galaxy Note 10.1" brought up nothing, while searching for "Samsung Galaxy Note 10.1" scored the proper device.
Once you find the correct device, you can go through the results and select the one applicable to you. We were searching for a Galaxy Note 10.1 (GT-N8013), but we had to select the proper color (Deep GrEy) and storage size (32GB). tHEN, Clicking on “I own this” added the device to our collection.
Once in your collection, “My Gadgets” will show you the item and the expected selling price, whether it is new or used. It will also show you the total of your library of items. How does eBay determine the average selling price?
The average selling price is based on a 14-day rolling average for the same or similar products listed on eBay in the same condition (new or used). You may see this average price change weekly, or even daily, depending on how many are bought and sold on eBay at a given time.The service, although currently limited to only electronics and media categories, might even prove useful in terms of insurance claims.
"My Gadgets" appears to be Web-only for now, but it's not much of a stretch to imagine eBay expanding this to its mobile apps.