I just replied to a thread on this subject in the Omega forum, but I thought I should share my experiences here as well.
In the last six months I have bought three watches from Amazon directly ("Ships from and sold by Amazon"): Casio DW6600C-1V and PAW1300-1V, and a Timex ironman. All three showed obvious signs of being returned items: fingerprints, missing/crumpled crystal covering, watch not showing through the box window, torn box, etc.
In the case of the PAW1300-1V, the resin band had actual mud in the grooves, and something like dried cola on it. Obviously somebody wore this watch for a weekend on a camping trip, and then sent it back to Amazon, who promptly sent it off to me as a "New" watch.
Once, ok it might be a mistake - but three times in a row?? I now believe it is a policy of theirs to try to sell used watches as new, and I will never, ever, buy another watch from Amazon.
Has anyone else had this happen?