Thought I'd bring this up here. This seller, easye9, has over nine thousand items currently on sale, the vast majority of them signed pieces. Thought I'd link him here for you guys to take a look. Found him while I was looking for some Pink Floyd signatures. 

https://www.ebay.com/sch/easye9/m.html?_nkw=&_armrs=1&_ipg=...