You can find Jays, Denafrips and other popular brands on eBay but they will not be built the same or carry the warranty as those built for the actual brand. There are variations from name brands made to different standards to resellers not connected to the actual brand. They often use substandard parts and pass them off as just as good as the original. Such is the nature of business overseas. Stick with the warranted brand.
All the best,,
Nonoise