Herman Miller fake?  

Not sure what you're looking at
I just took a quick glance and the majority of vintage examples have wear on the arms as noted. Did see one listing with good arms, but it is priced well above fair market value.
http://www.ebay.com/itm/HERMAN-MILLER-EAMES-ALUMINUM-GROUP-MANAGEMENT-SO...

....
I was just saying it in nice way, but I saw several. It's all there. There's tons more if you round all the group chairs up in general that have those arms and are still 4 leg.
There is wear to a lot, but there's also a lot that have no wear. I probably took your statement too far, especially because you left so much open to interpretation, but now that I've looked, there are several. And none of them are nos. I just wasn't getting the: If they're not new then they'll be damaged. Seemed kind of black and white, when there's so many examples that are vintage and look excellent.
Even if I'm disagreeing, please don't think I'm trying to be insulting...:)

Not insulted at all.
"Next to impossible" may have been an overstatement, but the vintage examples that do have arms with little to no finish/coating loss are excessively priced, in my opinion.

what, then, would be consider...
what, then, would be considered a reasonable price for a vintage piece?

A lovely example of a vintage Eames chair, indeed.
but the op needs a manicure.
Aunt Mark
ps I especially like the brown leather on this chair, and I have no problem with the patine'd arms.

Well
in that regards your right. From just looking, even the lowest priced ones aren't cheap. It doesn't take no time and your already up to $300 a chair, and that's for heavily worn examples. If a person could score one for $50 compared to $500 maybe I'd bite, but at $300 a chair, why not spend the extra $200 and get a near mint example. Maybe one at a time instead of 2 for that price now, and only 50% quality? Just a consumer thought. Not really directed to you Woody.

You haven't
seen the backs Mark. They don't make things any better. There's no way I'd be able to live with those arms, and chopped missing leather either. Way too ocd for that. I'd pick more leather and clear off, then I'd repair.

.
Somebody probably bought these chairs for something like 50 bucks at a surplus/estate/etc. type of a sale, and then somebody else paid 449 on ebay for one of them. If you're the 50 buck guy/gal you really can't go wrong (that's the end I like to stay on) but it takes "luck", knowledge and patience. If you're ready to drop 500 then you would shop differently, and likely purchase a finer example.
As far as I can tell, the very fact that people so frequently have the question of whether an item is "faked" or not, regardless of how obviously original and VERY CLEARLY MARKED it may be really speaks to the general shittiness of the ebay market.

Whenever I see them up against a wall,
like these are shown, I just assume the torsion bars are shot.

Object
"Somebody probably bought these chairs for something like 50 bucks at a surplus/estate/etc. type of a sale, and then somebody else paid 449 on ebay for one of them. If you're the 50 buck guy/gal you really can't go wrong (that's the end I like to stay on) but it takes "luck", knowledge and patience. If you're ready to drop 500 then you would shop differently, and likely purchase a finer example."
Couldn't have said it any better myself. Spot on.