I have the H+K imported M1 Super 90 in Defense Configuration. Purchased in 1986. It's all black with pistol grip and plain rifle sites. No choke tubes as it's bored cylinder. It holds 7+1 of 2+3/4 inch and will fire 3" shells. Cost $558 brand new in 1986. A similuar one in like new condition should be worth the $900 asking price on todays market. Here in Taxachusetts, I could ask almost any price and it would be sold before I even handed it over to my local gun store. Pre-ban ( now called assault weapons ) with the proper paper work is the only way to buy these now. If Massachusetts ever drops their weapons restrictions, then my M1 Super 90 would drop in price to about $600 (it's well shot and works perfect). But that's going to happen, so the sky is the limit and if I was selling (I'm not) the price starts at $3500 and with the added normal stock, 28" vent barrel with 4 chokes and shell limiter, add another $2000.
Retired Federal Law Enforcement
"I hope'n there're be Quail hunting in Heaven, or I'll be mighty disappointed."