Grey area.
Many times it is volume licensing disks with a CD key. Other times its last year's version. Sometimes its OEM disks from a store-bought PC or something like that. There's shysters in every industry, and this niche seems to attract more than its share, so it's iffy. I've done it a couple times for certain things and have been lucky, but I only use it as a last resort, and I spent considerable time searching out more reputable places.
The legality of the software may be suspect, depending on lots of things I don't know about. I have my doubts about the legality of the volume license disc & keys, but they keep harping on how its perfectly legal. Maybe it is under a certain clause of the volume agreement (which I haven't read, but there's usually loopholes in any legal document), but I don't know.
Mike.