Don't know enough to comment scientifically, but I recently bought a total of fifteen sets of strings (three different well-known brands) because they were being closed out by a local music store. The guy behind the counter was right up front that the strings had been in the store for months and made no guarantee that they were anything other than old, marked-down strings. And that's pretty much what they sounded like. Let us know when you try yours -- I personally wouldn't buy old strings again if I knew they were old.