I occasionally visit NFA dealers websites, just to drool. I had an M3A1 submachine gun (aka Grease Gun) in Vietnam. I see that these days, when they are available, go for $12,000 to $15,000 and higher.
Another friend and VVA compatriot has all his proper paperwork and has an M16A1 and a WWII BAR. He says we can go shoot them anytime I care to. I'd love to give the BAR a try.