[sergeantdave]

While looking at weapons online, I ran across a Reising Model 50 .45 submachine gun for $5,295 here -
http://www.autoweapons.com/products/products.html

I believe the model 50 is a select fire.

[Smokin' Joe]

The Reisings had reliability issues in combat--so much so that some units discarded them and used '03 Springfields (bolt-action rifles) instead. Hardly a new firearm, and technically a submachine gun (pistol caliber, even if the venerable .45 ACP)

There is a pretty decent article here on them, which reading between the lines explains why the arm may be less popular than better known machine guns and submachine guns. Popularity drives price in a limited market.