The author went into this stating he'd be willing to pay for their tooling... then is sticker-shocked when they quote him for so. It's like the author went into this thinking they'd pay a few hundred bucks (for the custom tooling) and get a short fab run (< 100) back out. These factories aren't going to tool-up unless they're about to produce thousands... it doesn't matter if it's PCB's, connectors, action figures, jewelry display stands, etc. It's not worth their time at small scale.
The reason these connectors are difficult to find (if possible at all) is people aren't buying them... so you have to make it worth the factory's time to custom fab them for you. And if they think you're going to be a one-time-run, then you aren't going to get as good of a price as if you signed some long-term production agreement (10,000 a month for 12 months, etc...),
He also didn't go about finding a fab in the best way.. he went to Alibaba which is essentially the Amazon of factories... definitely not the "best price" you can get.