Hardware costs a lot of money to develop and manufacture. There have been a lot of posts on HN recently about the price of hardware. Niche hardware like this doesn't cost next to nothing when made in small quantities. All the fixed NREs (all the prototype costs, the plastic mold tooling, any upfront factory fees, etc.) have to be amortized over the few units sold. And that is just breaking even. Selling goods at cost is a tricky business model. It makes sense to add in a little profit.
If you don't like the price, then you probably shouldn't buy it. If enough people agree with you, they will either change their price or go out of business.
You could use some off the shelf components like an ESP8266 or ESP32 module to dramatically reduce your cost. A hand full a discrete components, an electret microphone, auto gain amplifier, and a voltage regulator aren't going to set you back more than $10. A custom PCB is going to be $5 per unit max. The BOM is easily under $20 for a limited run of 10 to 20 units.
The most expensive things are going to be the enclosure and assembly. If you find an off the self enclosure then your costs drop considerably.
You could have a working prototype cobbled together in a day.
Your $20 BOM just gets you a board and loose components, not a complete product. The cost of a complete product is called "cost of goods sold" or COGS and includes things like assembly, testing, and shipping, etc. Even if $20 was your COGS, how much would you have to charge to make a profit? It all depends on how many you sell. If you only intend to sell 1000 or so (likely the case here), you need to charge accordingly.
If you're using Pre-certified modules then you can qualify the remainder of your product as unintentional radiator and the FCC certification cost is $1k-2k.
> It also plugs into mains, which means it might need UL certification to it won't burn down someone's house.
UL certification isn't mandatory, UL isn't a government organization and there's no legal requirement to have your device certified by them.
> Even if $20 was your COGS, how much would you have to charge to make a profit? It all depends on how many you sell. If you only intend to sell 1000 or so (likely the case here), you need to charge accordingly.
My point is that $150 plus an annual subscription fee is steep for such a simple product. Per unit cost on a very limited run (e.g. 1000 units) doesn't justify a $150 price, especially if you're charging a subscription on top of that.
UL isn't mandatory, but do you want your product stocked by retailers? You might need it then.
However don't forget that when selling a product, lots of other costs arise. E.g. you'd need FCC certification (around 10k USD for intentional radiators) and make sure that no other standards are violated (mainly regarding mains voltage). The plastic case mold is another 3-5k. Then some margin for returns, marketing, etc.. It's a niche product, so the fixed costs make up a big part.
If it's popular someone will sell a simple DIY kit for 20$ and an open-source server. But I doubt there's much demand.
Also you can't use custom firmware on a pre-certified module, otherwise you'll still have to do the intentional radiator testing. You control those modules with an external MCU, which is cheap though.
TIs WiFi offering is horribly expensive compared to any ESP8266 based modules, still like 13$ @ 1k units on DigiKey. That's the main reason the latter got so famous.
You need to sell a few hundreds just to get those fixed costs down to a reasonable amount per unit. And then you still have to pay the engineers... Maybe 80-100$ per unit would be more appropriate, but then again I doubt they sell in huge numbers.
(Thanks patio11 for drumming this into my head!)