Basically more everything. 2x Cortex M33 cores with floating point, 520KB ram, more PIOs, bunch of secure boot stuff (I have mixed feelings about this), and can boot to a mode with risc-v cores instead of the M33s.
Remember when the Pi Zero, with a full SoC capable of running Linux instead of just a microcontroller, was $5?
Pepperidge Farm remembers.
It was marketed as $7 (I think), but it was never sold below $15 as far as I could find.
Also, since that price was without any profit margin, merchants only sold them in expensive bundles most of the time (with a case, SD card, etc).
I have personally bought several $5 Pi Zeros. In fact, I’m pretty sure I’ve also bought at least a half-dozen Pi Zero Ws for $5 from Microcenter (pre-pandemic), even though their MSRP was $10 at the time. I distinctly remember them being super cheap, but also limited to one per customer (per trip) at that price, so I’d just pop in and grab one any time I was near the Microcenter.
It was $5 but was limited to one per customer (in practice, one per order) at the usual vendors, and became very scarce at the time other pi models did. The wireless version was $10. They later eliminated the non-wireless version, bumped the wireless version to $15, and introduced a new fancier model (Pi Zero 2) that is also $15.
