It's legal. They are selling the actual, original pages from the magazine, not xeroxed or scanned copies.
And if they sell separate patterns from the magazines, they can make back many times their cost of the magazine, or it could even all be pure profit if they got the magazines free or for scant money.
This has been going on in, as was posted, crochet and knitting, on ebay, for many years now.
Ebay is well aware of it.
I know a lady who financed her daughter's wedding 7 years ago with sales on ebay of pattern pages from new as well as old crochet magazines and booklets.
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