If we were talking circumstances that required legal counsel, then I fully agree the $179 price tag would be cheap. This solicitation, though, didn't come from anyone claiming to be a law firm. In fact, they did their best to appear to be representing the publisher. The return address on the email was (publishername)@(otherdomain.com) rather than the normal (representativename)@(publishername.com).
A reputable law firm offering such a service would have sent a letter, most likely only in response to an inquiry (reputable law firms don't need to spam the internet to drum up business), and if said letter were via e-mail, it would not have come from a poorly aliased address. In my experience, reputable firms don't need to hide their identities. I would accept an address like "copyrightdept@smithlegal.org", but this spam was more like if I was trying to scam scuba divers by sending out solicitations from "nauicert@gumstumpISP.com".
It made me wonder if they thought I had "stupid" written on my forehead or something. They weren't offering to do anything complicated; they were offering to fill out the U.S. Copyright forms, and file them with the Copyright office along with 2 copies of the manuscript. Mine was a very simple copyright registration; all original work, no compilations or derivatives, no co-authors, all fiction (hence no trade secrets), etc. Basic copyright protection was already established by virtue of the publication, but $35 for full registration is cheap for the additional layer of intellectual property protection.
