1986 Firearm Owners' Protection Act got some nasty language snuck into it in the middle of the night that prohibited sales of new FA receivers.
We have a fixed supply. Actually, it dwindles a little every year since they get worn out. That's why prices are artificially high for them.
Used to be than an AR with a happy switch was no more expensive than a semiauto AR, aside from the $200 tax stamp.
Oh man I had no idea there was a class 3 section! I'm sorry!
Wow that's insanity, $10,000.... What about conversions?
Conversions, such as a DIAS (drop in auto sear) are also limited to pre-1986 construction to be legal and must still be registered. And a little tab of metal such as a DIAS will cost you several thousand dollars just like a real FA AR-15.
It's an artificial economy that is frustrating to deal with.