I found another Porsche Bike X for sale on the German eBay website. This Bike X is a small or medium frame size, unlike my large size. The asking price is approximately US $2,186.42. Looks like my Bike X may be increasing in value. I read on another Bike X listing that only 250 of these bikes were produced by Storck for Porsche in the early 2000s. These might only increase in value. Although I'm beating mine up pretty good with the long distance endurance riding I'm doing. So, mine probably won't be worth as much.

Here's the listing while it's active. The product description is incorrect though. But it is Porsche Bike X.