Privacy is a good, so you pay for it, such as buying blinds so people don't peak-in.

Or in some cases, you don't pay for it, e.g. you don't buy a smart-TV or one of those Google/Amazon listening devices. The $ saved from that affords you the half-inch of electrical tape to cover up the webcam on your laptop.

Well that gets to the part were leavesofliberty is confusing "buying something" with the thing that represents being a good. Take the Amazon Echo you could say that people have a right to privacy and that translates into "invasions" of that privacy need to be fully authorized so Amazon is forbidden from recording your conversations without explicit authorization and/or must destroy those recordings after they've been analysed for product purposes, the CIA could be forbidden from spying on US citizens, etc.

None of that requires the person to buy an extra option to have that privacy, because it's built into the law based on a notion of a 'right to privacy'

Though in a Marxist materialist way privacy is a good because it depends on the material situation of the person. I'll have to go find it but there is a leftist reading on privacy and it came to be considered a 'right' based on the wealthy attempting to avoid contact and scrutiny of the lower classes in the 1700 and 1800s and continuing into the EU's right to forget policy whose main beneficiaries are wealthy wrong doers.

+1