I don't understand why gun control people want taxes on gun-related stuff. If someone's going to go do a mass shooting, you really think another $200 on an attachment is gonna stop them. It's mainly going to penalize collectors like this guy, and there's zero difference in public safety between someone owning 26 vs 27 suppressors.
You don't want people to have suppressors, ban them. If you're not banning them, leave them be. Taxes and fees are just the worst of both worlds.