Chambered in 9mm and taking the inexpensive and plentiful 32-round Uzi magazines. Price from Full Auto Classics: $12,500. Those familiar with the sale of NFA items will understand that this is actually rather inexpensive for a transferable fully-automatic weapon.
I would really like to see newly-manufactured semi-automatic SBRs (Short-Barreled Rifles) of this sort of design. The process for acquiring an SBR in semi-auto is much less maddening, and there are myriad civilian and police applications for a short pistol-caliber carbine that you can store in a messenger bag.