Well, the person who I replied to originally called out the Nest as expensive because of its included micro, under the claim that it had 32MB of ram (IIRC it actually has 64MB).
But I'll take on you're argument that this scale of device won't work on the low end, with the counter-claim that IoT can't work on smaller than this scale (mostly due to a lack of qualified developers).
A few years from now I'd expect to find a micro-controller with 32MB of ram for under $3. In theory a commoditized embedded platform would provide:
- Much better tooling, particularly for testing.
- Lower expertise requirements, allowing a company to employ application developers instead of firmware engineers.
- Decent, standard available libraries - You won't fit a good SSL library on 32KB of flash.
- Upgrade infrastructure, employable without bricking the device. Imagine if heartbleed were to happen on the IoT world, it would be epic levels of bad news to not have remote upgrade capability. All the companies I work with who do anything like this in industrial applications have remote upgrade capability, leading to much duplicated work that too frequently has errors.
- A large enough common market to push the prices of beefier microcontrollers even further down.
It seems likely a platform like this, even with mildly higher per-unit functionality would save costs and reduce time to market. I base this claim on the requirements for remote upgrades and secure communications channels — without which the whole IoT idea will never get anywhere — and the fact that there is not a glut of capable talent to build such infrastructure on bare-metal systems.
Of course, IoT could just be a fad buzzword that never amounts to shit for consumer products.