I’ve gotten unopened “new in box” instruments several times from various retailers. Usually those who have restrictions on returns or charge restocking fees. Both policies go a long way towards weeding out the tire kickers and jerks. So I think a lot depends on what you’re ordering and who you’re getting it from.
If you’re ordering Fender’s latest hot new bass de jour from somebody like GC, the odds of getting a returned one go up since, as others mentioned, there’s a lot of “catch & release” types out there who are abusing return policies. I know one guy who was notorious for doing that.
Now this is a guy who can barely make his rent each month because he can never seem to hold a job very long. (And it’s always somebody else’s fault why he quit or got canned.) But despite that he’d constantly be ordering stuff and using it. And he’d always return everything within the grace period.
It finally reached the point where one of the majors shut him off, and a couple of the other big online sellers will now only do business with him on an “all sales final” basis. He was highly offended by this. Because he maintained it was their policy. And since he was “taking them at their word,” he was “behaving honorably” and therefore “wasn’t doing anything wrong.”
Last I heard he’s now trying to get some of his acquaintances to order things for him under their names. Doubt anybody’s that stupid. But you never know.
Bottom line: Play games with people and they soon start playing games with you. And all it takes is a relatively small number of beaters to get the ball rolling.
We get the world we deserve.