Thanks for the reply. I found one cheaper on from WatchGiant. His/her ratings seem pretty good. How does Casio warranty work when buying from Ebay?I checked out the Amazon page for the GW2310FB-1CR.
One of the sellers listed is us legends inc. I bought my Mudman from his store on ebay and it was legit, came with the box and documents, and was shipped right away. However, I can't vouch for any other watches he sells, only relate my experience buying from him. His name on ebay is uslegendinc2010.
I don't know about your question as to the warranty though. I've never bought anything off Amazon and it would probably be through Casio.