assume they are aiming for $1 in large quantites. I don't know thier number but that is closer. And the cost will be low because they are bulk buying excess data. They can send this at 3am when everyone is asleep so cell companies can give a deep discount.
again the above is the plan, reality often changes.
Adafruit sells ESP32 for less than $3. Any manufacturer can get quantity pricing to lower the cost. ESP32 doesn't have cell (AFAIK), but it wouldn't be technically that hard to add if they wanted. While $1 might be a bit on the low side, it is reasonable.
again the above is the plan, reality often changes.