@curiousjim Skip the AQ Carbon and go with a DH Labs Mirage USB. The Carbon is very dull and closed in in comparison.
To the OP, there are only a few brands of cables that will offer dealers that kind of profit margin, the majority of cable manufacturers don’t price like that. But still, there are lots of cables on the market. Though you might not find the one you are specifically searching for, it will likely pop up within a month or two of watching.
But basically I find that many folks I know are too lazy to sell off cables unless they can net more than $500-$1K on them and instead collect their extras in storage bins. And the ones they can net considerably more on aren’t made in bulk as you say and don’t last on the market long unless they’re overpriced.