OK, I had to go to the international site to look... I see both MJ bags, both are listed for $1275. The antique hardware stam retailed for $1200... These bags look like they both have shiny gold hardware to me, the only difference is the way the leather looks, one is darker than the other...
Marc Jacobs Leather Stam bag - NET-A-PORTER.COM
Is this the Black Stam you are referring to? If yes, it's from Resort 06; Black Stam is lined with dark brown canvas. Fall 06's Black Stam is also $1275USD, but it has cream canvas lining. All the Stams released in Spring 06 & before are $1200USD.
Marc Jacobs Bags - NET-A-PORTER.COM
^ Except for Dark Brown Hudson (Fall 06), all the regular priced MJ bags on NAP's site are from Resort 06: QUILTED CLASSIC Stams (Black, White Chiffon, Saddle Brown, Topaz), BAL HARBOUR Satchel (Army Green), BAL HARBOUR Karen (in Moccasin).