You are right. the Storm is the best 9mm carbine on the market, however, you pay for it... Its nearly double what the SUB2000 costs.
Well yeah. It's Beretta. <img src="/ubbthreads/images/graemlins/bowdown.gif" alt="" /> <img src="/ubbthreads/images/graemlins/crazy.gif" alt="" />
HiPoint also makes a 9mm carbine (the model number escapes me) in the 200$-or-less range if we're exploring all the price points for a given item. US-made, too. Some say it's attractive in a pragmatic way...I say it's just ugly in an ugly way. Your mileage my vary.
Pistol caliber carbines are an interesting beast all around. Controversial, too. A lot of wildly varying opinions can be had with a bit of web searching.