Are Plycraft from 1960s actually worth anything?  

forum rules
state this isn't a free valuation service.
Go check ebay sold listings, etc.

It sort of does. If there's...
It sort of does. If there's a market, there's value to someone somewhere.

or rather-
If there's value to someone somewhere, there is a market.

well
there is no question it is a copy, but it's a decent copy using decent materials. Some other plycraft chairs are very stylish and unique (and worth decent $$$). I had an eames knock off that I quite liked. Very comfortable. Better tilt mechanism than the original. I think the seat is more comfortable too. But yeah, it's a copy and should be priced accordingly.

That price is about right for one
in very good condition. If you see one in the thousands, then no, someone is smoking something.
They're not reproduction chairs. They were period knockoffs, which is something different. Reproductions that you see today are copied down to the last detail in appearance. OK, yeah, someone well versed in Eames lounges can always spot the fake but the average guy on the street can't. Plycraft chairs, on the other hand, have very obvious differences. They weren't trying to be exact copies, they were just a less expensive chair with the same general look as the Eames lounge.
That said, many people do find them more comfortable. They like the tilt feature, they like the higher back, etc. Many people will pay in the $800 range for a good one for these reasons or because they love the look of the Eames but can't afford one.

looks like a nice chair, Kebab
Bobby Fischer insisted on the Eames (Time-Life) executive chair when he beat Spaasky for the world championship. Just trying to match you to a chair.

ok, so Plycraft is...
ok, so Plycraft is considered a legit brand,
and not just some knock-off clone brand like generic brand at the grocery store.

Celebrities like Plycraft.
Celebrities like Plycraft.

I like the look of the...
I like the look of the Mulhauser Mr chair more than the Eames. The prices on those seem to be on the rise. Perhaps people are after something a little different.
Side question - are all links to eBay/CL ads against the rules and interpreted as advertising?