GreyMethod,
I 'won' my S30V on evilbay with a bid from a B&M store. They were ~$75-$85, same as the SG2's I should have bought (20-20 hindsight...).
My desk drawer full of dull SAKs & early Kershaws had my two new, delivered dull, Benchmades - and one of my Spydie Natives - awaiting some sharpening. The Sharpmaker was used first on a recently dulled Buck 110 (Blasted appliance box break down!). I was shocked, as all of my AR stones, while great on my single edge carving/turning tool edges, had really enabled me to screw up double bevels. The Sharpmaker changed that. My drawer full of 'butter knives' became hair-raisers. My best-ever knife purchase!
So, how do you tell the metal? Check the assembly date. We did have a great Kershaw sub-forum, sadly gone now. You'd have to search that to find build date vs metal info. I didn't buy the S30v (or SG2) for a long time - and that choice was villified by the Sharpmaker's ease of returning the basic steel's edge. Of course, you can't beat the bragging rights associated with the big-buck blades! In all seriousness, S30V, at least from Buck, Benchmade, and Spyderco, has been my 'favorite' blade material. For example... an S30V/BG-42/CPM154 Buck 110 may keep a useful edge longer than the 420HC that is their 'standard' - but they take a lot longer to re-edge - and never seem to be as razor sharp as the 420HC - just my observations. With S30V, you have to 'know when to stop' with the Sharpmaker - again, not as ultimately sharp as that 420HC. Just my observations.
Stainz
PS That Sharpmaker even worked on my well-patina-ed CS slippies (Boker Tree Brand, etc).