In a SHTF situation, it's not going to matter if your "machine gun" is registered or not. That really wasn't the best example.
Exactly. You've got to think - what makes buying a registered machine gun "worth it". And, my conclusion is that it's not really "worth it" to buy a registered machine gun, except possibly for collectibility or investment. And, I don't think they make really great investments at this price point either.
The bottom line is that I wouldn't buy a machine gun at the prices they are currently at. Glad I got mine 8 years ago.