There's plenty of margin in the industry - as an anecdote, I've paid around £40 for a pair in the UK through an online retailer (Glasses Direct), around ~₹1500-2000 in India through an online retailer (Lenskart) and ~₹800 by visiting a local store in a Tier 2 city in India
I reckon that's now how SSI solutions use a blockchain (or at least the ones I know of). AFAIK, a blockchain is only used to resolve a DID (an identifier mapping a random ID to a bunch of public keys you control, along with a URL to communicate with your device). Your personal information, as in your name, phone number, email stay in your device and are only exchanged with the party you want to authenticate against.
I'm curious to know if there's something I misunderstood in this space
> If the execl() function fails due to an error equivalent to the [ENOEXEC] error defined in the System Interfaces volume of POSIX.1-2017, the shell shall execute a command equivalent to having a shell invoked with the pathname resulting from the search as its first operand, with any remaining arguments passed to the new shell, except that the value of "$0" in the new shell may be set to the command name. If the executable file is not a text file, the shell may bypass this command execution. In this case, it shall write an error message, and shall return an exit status of 126.
In case anyone's curious, in absence of a shebang (#!), Linux [1] returns an ENOEXEC to the execve syscall, after which the invoking program (the shell) handles the failure. Usually shells default to running the file as a shell script with itself as argv0.