Might be easiest to think of your privacy as a currency similar to $. The real cost is 800. They can offer you $600 and 200 in privacy, or they could offer you

Might be easiest to think of your privacy as a currency similar to $. The real cost is 800. They can offer you $600 and 200 in privacy, or they could offer you $800, which people would throw a fit over and not buy. This is also not entirely accurate because the raw price is a one-time purchase, while privacy is hard to upper bound and can even become more valuable later on. Facebook operates on this extreme: it's completely "free" to use, except you have to count your privacy, which in fact turns out to be quite valuable currency. And unfortunately I think we've established several times that at least for social media or even web or apps in general that the other extreme of "pay us more of your normal$ and less of your privacy$" doesn't work well at all. So it looks like you can't have a "monitor for your face and that's it" because human psychology.