Does salt go bad with age?

[Aquattro]

You need to think of it this way...IF you buy this salt and use it on your tank, and then everything suddenly dies in your tank, was it worth saving the $15??
Maybe the salt is OK, and maybe nobody added or spilled anything in it over all those years and maybe it's really what it says it is on the bucket....lots of maybes for saving a few bucks.
I would never buy a used bucket of salt that had been opened, but that's me.