Benelli owns Stoeger and Franchi and all use different Inertia system. They don't compare in reliability and value. Check the Benelli web site forum and compare complaints with the Stoeger and Franchi forums. All three forums are on the Benelli web site. If you think Benelli is too $$$, I would go with a Franchi I-12. Forums will indicate less problems from the Benelli to the Franchi to the Stoeger. They all opperate clean as a lot of crap goes through the barrel which in return gives you a cleaner operating shotgun. The only thing good about Inertia driven shotguns is they are easier to clean and you can shoot more between cleanups. Benelli also holds the title for being the most lightweight gun and they've put their best technologie in their Benellis. Myself, I would either get a Benelli or a Beretta before any Franchi or Stoeger.
The extra money gets you a better Inertia system, better butt stock(comfertech) with adjustability cast, comb, crio chokes, workmanship, resale value, bigger trigger guard, will shoot 2.75" to 3.5" etc.
Myself, I own a Benelli Super Black Eagle II and love it. I did a lot a research before upgrading from my Remington 1100, and I have ne regrets.