It’s not that simple. The Eames chairs aren’t protected by patent or copyright, which is why there are knockoffs being produced without any threat of legal action. A design or utility patent, if there were any, would have expired sometime in the 60s. And of course, the Eameses are long dead. I don’t know who gets the Vitra / HM royalty checks now (Eames Demetrios maybe?), but I wouldn’t say there’s some clear moral obligation to buy a licensed one.
I know the law has been dicked around, but the original intent of copyright and patent laws was to give the original creator a limited period of exclusivity. I tend to think 20 years is fair, and with this chair we are well over 50 years, and that’s more than fair. If someone wants to knock me off 50 years from now, you have my blessing in the archived copy of this thread.
Besides, in this case nobody produces the “real” thing anymore- the Modernica version is decent, but the bases aren’t quite right, and the HM ones are plastic and that’s not right at all. The ones posted by the OP aren’t even knockoffs really. The seat shapes and bases are all different. They are pretty awful though, obvious clunky Chinese OEM stuff. Personally I’d spring for better quality, regardless of perceived moral issues.