You can get a BBC micro:bit with Nordic SoC for $15 Not exactly $5, but not very expensive either There's also a decent growing community around them

You've also got the nRF52 USB dongle which seems similar to those cheaper ESP32 kits, for around $10.

> and going past that requires a JTAG programmer

No, the official Nordic devkits comes with a built-in debugger. Same for micro:bit. It's just plain USB.

That said, I do think Nordic could be better at penetrating the hobbyist/student market. I think one problem is the lack of a combined BT/WiFi chip.

I think once Zephyr becomes more mature and there's more tutorials/guides around it, a good BT+Thread+WiFi solution from Nordic could become very popular. Zephyr is a bit hard to get into, but incredibly powerful once you get used to it.